TensorFlow.NET/test/TensorFlowNET.UnitTest/nest_test/NestTest.cs

using System.Collections;
using System.Collections.Generic;
using Colorful;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Newtonsoft.Json.Linq;
using NumSharp;
using Tensorflow;
using Tensorflow.Util;
using static Tensorflow.Python;

namespace TensorFlowNET.UnitTest.nest_test
{
    /// <summary>
    /// excerpt of tensorflow/python/framework/util/nest_test.py
    /// </summary>
    [TestClass]
    public class NestTest : PythonTest
    {
        [TestInitialize]
        public void TestInitialize()
        {
            tf.Graph().as_default();
        }

        //public class PointXY
        //{
        //    public double x;
        //    public double y;
        //}

        //  if attr:
        //    class BadAttr(object):
        //      """Class that has a non-iterable __attrs_attrs__."""
        //      __attrs_attrs__ = None

        //    @attr.s
        //    class SampleAttr(object):
        //      field1 = attr.ib()
        //      field2 = attr.ib()

        //  @test_util.assert_no_new_pyobjects_executing_eagerly
        //  def testAttrsFlattenAndPack(self) :
        //    if attr is None:
        //      self.skipTest("attr module is unavailable.")

        //    field_values = [1, 2]
        //        sample_attr = NestTest.SampleAttr(* field_values)
        //        self.assertFalse(nest._is_attrs(field_values))
        //    self.assertTrue(nest._is_attrs(sample_attr))
        //    flat = nest.flatten(sample_attr)
        //    self.assertEqual(field_values, flat)
        //    restructured_from_flat = nest.pack_sequence_as(sample_attr, flat)
        //    self.assertIsInstance(restructured_from_flat, NestTest.SampleAttr)
        //    self.assertEqual(restructured_from_flat, sample_attr)

        //# Check that flatten fails if attributes are not iterable
        //    with self.assertRaisesRegexp(TypeError, "object is not iterable"):
        //      flat = nest.flatten(NestTest.BadAttr())

        [TestMethod]
        public void testFlattenAndPack()
        {
            object structure = new object[] { new object[] { 3, 4 }, 5, new object[] { 6, 7, new object[] { 9, 10 }, 8 } };
            var flat = new List<object> { "a", "b", "c", "d", "e", "f", "g", "h" };

            self.assertEqual(nest.flatten(structure), new[] { 3, 4, 5, 6, 7, 9, 10, 8 });
            self.assertEqual(JArray.FromObject(nest.pack_sequence_as(structure, flat)).ToString(),
                JArray.FromObject(new object[] { new object[] { "a", "b" }, "c", new object[] { "d", "e", new object[] { "f", "g" }, "h" } }).ToString());
            structure = new object[] { new Hashtable { ["x"] = 4, ["y"] = 2 }, new object[] { new object[] { new Hashtable { ["x"] = 1, ["y"] = 0 }, }, } };
            flat = new List<object> { 4, 2, 1, 0 };
            self.assertEqual(nest.flatten(structure), flat);
            var restructured_from_flat = nest.pack_sequence_as(structure, flat) as object[];
            //Console.WriteLine(JArray.FromObject(restructured_from_flat));
            self.assertEqual(restructured_from_flat, structure);
            self.assertEqual((restructured_from_flat[0] as Hashtable)["x"], 4);
            self.assertEqual((restructured_from_flat[0] as Hashtable)["y"], 2);
            self.assertEqual((((restructured_from_flat[1] as object[])[0] as object[])[0] as Hashtable)["x"], 1);
            self.assertEqual((((restructured_from_flat[1] as object[])[0] as object[])[0] as Hashtable)["y"], 0);

            self.assertEqual(new List<object> { 5 }, nest.flatten(5));
            flat = nest.flatten(np.array(new[] { 5 }));
            self.assertEqual(new object[] { np.array(new int[] { 5 }) }, flat);

            self.assertEqual("a", nest.pack_sequence_as(5, new List<object> { "a" }));
            self.assertEqual(np.array(new[] { 5 }),
                nest.pack_sequence_as("scalar", new List<object> { np.array(new[] { 5 }) }));

            Assert.ThrowsException<ValueError>(() => nest.pack_sequence_as("scalar", new List<object>() { 4, 5 }));

            Assert.ThrowsException<ValueError>(() =>
                nest.pack_sequence_as(new object[] { 5, 6, new object[] { 7, 8 } }, new List<object> { "a", "b", "c" }));
        }

        //  @parameterized.parameters({"mapping_type": collections.OrderedDict
        //    },
        //                            {"mapping_type": _CustomMapping
        //})
        //  @test_util.assert_no_new_pyobjects_executing_eagerly
        //  def testFlattenDictOrder(self, mapping_type) :
        //    """`flatten` orders dicts by key, including OrderedDicts."""
        //    ordered = mapping_type([("d", 3), ("b", 1), ("a", 0), ("c", 2)])
        //    plain = {"d": 3, "b": 1, "a": 0, "c": 2}
        //    ordered_flat = nest.flatten(ordered)
        //    plain_flat = nest.flatten(plain)
        //    self.assertEqual([0, 1, 2, 3], ordered_flat)
        //    self.assertEqual([0, 1, 2, 3], plain_flat)

        //  @parameterized.parameters({"mapping_type": collections.OrderedDict},
        //                            {"mapping_type": _CustomMapping})
        //  def testPackDictOrder(self, mapping_type):
        //    """Packing orders dicts by key, including OrderedDicts."""
        //    custom = mapping_type([("d", 0), ("b", 0), ("a", 0), ("c", 0)])
        //    plain = {"d": 0, "b": 0, "a": 0, "c": 0}
        //    seq = [0, 1, 2, 3]
        //custom_reconstruction = nest.pack_sequence_as(custom, seq)
        //plain_reconstruction = nest.pack_sequence_as(plain, seq)
        //    self.assertIsInstance(custom_reconstruction, mapping_type)
        //    self.assertIsInstance(plain_reconstruction, dict)
        //    self.assertEqual(
        //        mapping_type([("d", 3), ("b", 1), ("a", 0), ("c", 2)]),
        //        custom_reconstruction)
        //    self.assertEqual({"d": 3, "b": 1, "a": 0, "c": 2}, plain_reconstruction)

        //  Abc = collections.namedtuple("A", ("b", "c"))  # pylint: disable=invalid-name

        //  @test_util.assert_no_new_pyobjects_executing_eagerly
        //  def testFlattenAndPack_withDicts(self) :
        //    # A nice messy mix of tuples, lists, dicts, and `OrderedDict`s.
        //    mess = [
        //        "z",
        //        NestTest.Abc(3, 4), {
        //            "d": _CustomMapping({
        //                41: 4
        //            }),
        //            "c": [
        //                1,
        //                collections.OrderedDict([
        //                    ("b", 3),
        //                    ("a", 2),
        //                ]),
        //            ],
        //            "b": 5
        //        }, 17
        //    ]

        //    flattened = nest.flatten(mess)
        //    self.assertEqual(flattened, ["z", 3, 4, 5, 1, 2, 3, 4, 17])

        //    structure_of_mess = [
        //        14,
        //        NestTest.Abc("a", True),
        //        {
        //            "d": _CustomMapping({
        //                41: 42
        //            }),
        //            "c": [
        //                0,
        //                collections.OrderedDict([
        //                    ("b", 9),
        //                    ("a", 8),
        //                ]),
        //            ],
        //            "b": 3
        //        },
        //        "hi everybody",
        //    ]

        //    unflattened = nest.pack_sequence_as(structure_of_mess, flattened)
        //    self.assertEqual(unflattened, mess)

        //    # Check also that the OrderedDict was created, with the correct key order.
        //unflattened_ordered_dict = unflattened[2]["c"][1]
        //    self.assertIsInstance(unflattened_ordered_dict, collections.OrderedDict)
        //    self.assertEqual(list(unflattened_ordered_dict.keys()), ["b", "a"])

        //    unflattened_custom_mapping = unflattened[2]["d"]
        //    self.assertIsInstance(unflattened_custom_mapping, _CustomMapping)
        //    self.assertEqual(list(unflattened_custom_mapping.keys()), [41])

        [TestMethod]
        public void testFlatten_numpyIsNotFlattened()
        {
            var structure = np.array(1, 2, 3);
            var flattened = nest.flatten(structure);
            self.assertEqual(len(flattened), 1);
        }

        [TestMethod]
        public void testFlatten_stringIsNotFlattened()
        {
            var structure = "lots of letters";
            var flattened = nest.flatten(structure);
            self.assertEqual(len(flattened), 1);
            var unflattened = nest.pack_sequence_as("goodbye", flattened);
            self.assertEqual(structure, unflattened);
        }

        //  def testPackSequenceAs_notIterableError(self) :
        //    with self.assertRaisesRegexp(TypeError,
        //                                 "flat_sequence must be a sequence"):
        //      nest.pack_sequence_as("hi", "bye")

        [TestMethod]
        public void testPackSequenceAs_wrongLengthsError()
        {
            Assert.ThrowsException<ValueError>(() =>
            {
                //    with self.assertRaisesRegexp(
                //        ValueError,
                //        "Structure had 2 elements, but flat_sequence had 3 elements."):
                nest.pack_sequence_as(new object[] { "hello", "world" }, new object[] { "and", "goodbye", "again" });
            });
        }

        [TestMethod]
        public void testIsSequence()
        {
            self.assertFalse(nest.is_sequence("1234"));
            self.assertTrue(nest.is_sequence(new object[] { 1, 3, new object[] { 4, 5 } }));
            // TODO: ValueTuple<T,T>
            //self.assertTrue(nest.is_sequence(((7, 8), (5, 6))));
            self.assertTrue(nest.is_sequence(new object[] { }));
            self.assertTrue(nest.is_sequence(new Hashtable { ["a"] = 1, ["b"] = 2 }));
            self.assertFalse(nest.is_sequence(new HashSet<int> { 1, 2 }));
            var ones = array_ops.ones(new int[] { 2, 3 });
            self.assertFalse(nest.is_sequence(ones));
            self.assertFalse(nest.is_sequence(gen_math_ops.tanh(ones)));
            self.assertFalse(nest.is_sequence(np.ones(new int[] { 4, 5 })));
        }

        //  @parameterized.parameters({"mapping_type": _CustomMapping},
        //                            {"mapping_type": dict})
        //  def testFlattenDictItems(self, mapping_type):
        //    dictionary = mapping_type({ (4, 5, (6, 8)): ("a", "b", ("c", "d"))})
        //    flat = {4: "a", 5: "b", 6: "c", 8: "d"}
        //    self.assertEqual(nest.flatten_dict_items(dictionary), flat)

        //    with self.assertRaises(TypeError):
        //      nest.flatten_dict_items(4)

        //    bad_dictionary = mapping_type({ (4, 5, (4, 8)): ("a", "b", ("c", "d"))})
        //    with self.assertRaisesRegexp(ValueError, "not unique"):
        //      nest.flatten_dict_items(bad_dictionary)

        //    another_bad_dictionary = mapping_type({
        //        (4, 5, (6, 8)): ("a", "b", ("c", ("d", "e")))
        //    })
        //    with self.assertRaisesRegexp(
        //        ValueError, "Key had [0-9]* elements, but value had [0-9]* elements"):
        //      nest.flatten_dict_items(another_bad_dictionary)

        //# pylint does not correctly recognize these as class names and
        //# suggests to use variable style under_score naming.
        //# pylint: disable=invalid-name
        //  Named0ab = collections.namedtuple("named_0", ("a", "b"))
        //  Named1ab = collections.namedtuple("named_1", ("a", "b"))
        //  SameNameab = collections.namedtuple("same_name", ("a", "b"))
        //  SameNameab2 = collections.namedtuple("same_name", ("a", "b"))
        //  SameNamexy = collections.namedtuple("same_name", ("x", "y"))
        //  SameName1xy = collections.namedtuple("same_name_1", ("x", "y"))
        //  SameName1xy2 = collections.namedtuple("same_name_1", ("x", "y"))
        //  NotSameName = collections.namedtuple("not_same_name", ("a", "b"))
        //  # pylint: enable=invalid-name

        //  class SameNamedType1(SameNameab):
        //    pass

        //  @test_util.assert_no_new_pyobjects_executing_eagerly
        //  def testAssertSameStructure(self):
        //    structure1 = (((1, 2), 3), 4, (5, 6))
        //    structure2 = ((("foo1", "foo2"), "foo3"), "foo4", ("foo5", "foo6"))
        //    structure_different_num_elements = ("spam", "eggs")
        //    structure_different_nesting = (((1, 2), 3), 4, 5, (6,))
        //    nest.assert_same_structure(structure1, structure2)
        //    nest.assert_same_structure("abc", 1.0)
        //    nest.assert_same_structure("abc", np.array([0, 1]))
        //    nest.assert_same_structure("abc", constant_op.constant([0, 1]))

        //    with self.assertRaisesRegexp(
        //        ValueError,
        //        ("The two structures don't have the same nested structure\\.\n\n"
        //         "First structure:.*?\n\n"
        //         "Second structure:.*\n\n"
        //         "More specifically: Substructure "
        //         r'"type=tuple str=\(\(1, 2\), 3\)" is a sequence, while '
        //         'substructure "type=str str=spam" is not\n'
        //         "Entire first structure:\n"
        //         r"\(\(\(\., \.\), \.\), \., \(\., \.\)\)\n"
        //         "Entire second structure:\n"
        //         r"\(\., \.\)")):
        //      nest.assert_same_structure(structure1, structure_different_num_elements)

        //    with self.assertRaisesRegexp(
        //        ValueError,
        //        ("The two structures don't have the same nested structure\\.\n\n"
        //         "First structure:.*?\n\n"
        //         "Second structure:.*\n\n"
        //         r'More specifically: Substructure "type=list str=\[0, 1\]" '
        //         r'is a sequence, while substructure "type=ndarray str=\[0 1\]" '
        //         "is not")):
        //      nest.assert_same_structure([0, 1], np.array([0, 1]))

        //    with self.assertRaisesRegexp(
        //        ValueError,
        //        ("The two structures don't have the same nested structure\\.\n\n"
        //         "First structure:.*?\n\n"
        //         "Second structure:.*\n\n"
        //         r'More specifically: Substructure "type=list str=\[0, 1\]" '
        //         'is a sequence, while substructure "type=int str=0" '
        //         "is not")):
        //      nest.assert_same_structure(0, [0, 1])

        //    self.assertRaises(TypeError, nest.assert_same_structure, (0, 1), [0, 1])

        //    with self.assertRaisesRegexp(
        //        ValueError,
        //        ("don't have the same nested structure\\.\n\n"
        //         "First structure: .*?\n\nSecond structure: ")):
        //      nest.assert_same_structure(structure1, structure_different_nesting)

        //    self.assertRaises(TypeError, nest.assert_same_structure, (0, 1),
        //                      NestTest.Named0ab("a", "b"))

        //    nest.assert_same_structure(NestTest.Named0ab(3, 4),
        //                               NestTest.Named0ab("a", "b"))

        //    self.assertRaises(TypeError, nest.assert_same_structure,
        //                      NestTest.Named0ab(3, 4), NestTest.Named1ab(3, 4))

        //    with self.assertRaisesRegexp(
        //        ValueError,
        //        ("don't have the same nested structure\\.\n\n"
        //         "First structure: .*?\n\nSecond structure: ")):
        //      nest.assert_same_structure(NestTest.Named0ab(3, 4),
        //                                 NestTest.Named0ab([3], 4))

        //    with self.assertRaisesRegexp(
        //        ValueError,
        //        ("don't have the same nested structure\\.\n\n"
        //         "First structure: .*?\n\nSecond structure: ")):
        //      nest.assert_same_structure([[3], 4], [3, [4]])

        //    structure1_list = [[[1, 2], 3], 4, [5, 6]]
        //    with self.assertRaisesRegexp(TypeError,
        //                                 "don't have the same sequence type"):
        //      nest.assert_same_structure(structure1, structure1_list)
        //    nest.assert_same_structure(structure1, structure2, check_types= False)
        //    nest.assert_same_structure(structure1, structure1_list, check_types=False)

        //    with self.assertRaisesRegexp(ValueError,
        //                                 "don't have the same set of keys"):
        //      nest.assert_same_structure({"a": 1}, {"b": 1})

        //    nest.assert_same_structure(NestTest.SameNameab(0, 1),
        //                               NestTest.SameNameab2(2, 3))

        //    # This assertion is expected to pass: two namedtuples with the same
        //    # name and field names are considered to be identical.
        //    nest.assert_same_structure(
        //        NestTest.SameNameab(NestTest.SameName1xy(0, 1), 2),
        //        NestTest.SameNameab2(NestTest.SameName1xy2(2, 3), 4))

        //    expected_message = "The two structures don't have the same.*"
        //    with self.assertRaisesRegexp(ValueError, expected_message):
        //      nest.assert_same_structure(
        //          NestTest.SameNameab(0, NestTest.SameNameab2(1, 2)),
        //          NestTest.SameNameab2(NestTest.SameNameab(0, 1), 2))

        //    self.assertRaises(TypeError, nest.assert_same_structure,
        //                      NestTest.SameNameab(0, 1), NestTest.NotSameName(2, 3))

        //    self.assertRaises(TypeError, nest.assert_same_structure,
        //                      NestTest.SameNameab(0, 1), NestTest.SameNamexy(2, 3))

        //    self.assertRaises(TypeError, nest.assert_same_structure,
        //                      NestTest.SameNameab(0, 1), NestTest.SameNamedType1(2, 3))

        //  EmptyNT = collections.namedtuple("empty_nt", "")  # pylint: disable=invalid-name

        //  def testHeterogeneousComparison(self):
        //    nest.assert_same_structure({"a": 4}, _CustomMapping(a= 3))
        //    nest.assert_same_structure(_CustomMapping(b=3), {"b": 4})

        [TestMethod]
        public void testMapStructure()
        {
            var structure1 = new object[] { new object[] { new object[] { 1, 2 }, 3 }, 4, new object[] { 5, 6 } };
            var structure2 = new object[] { new object[] { new object[] { 7, 8 }, 9 }, 10, new object[] { 11, 12 } };
            var structure1_plus1 = nest.map_structure(x => (int)x + 1, structure1);
            var structure1_strings = nest.map_structure(x => $"{x}", structure1);
            var s = JArray.FromObject(structure1_plus1).ToString();
            Console.WriteLine(s);
            //    nest.assert_same_structure(structure1, structure1_plus1)
            self.assertAllEqual( nest.flatten(structure1_plus1), new object[] { 2, 3, 4, 5, 6, 7 });
            self.assertAllEqual(nest.flatten(structure1_strings), new object[] { "1", "2", "3", "4", "5", "6" });
            var structure1_plus_structure2 = nest.map_structure(x => (int)(x[0]) + (int)(x[1]), structure1, structure2);
            self.assertEqual(
                new object[] { new object[] { new object[] { 1 + 7, 2 + 8}, 3 + 9}, 4 + 10, new object[] { 5 + 11, 6 + 12}},
                structure1_plus_structure2);

            //    self.assertEqual(3, nest.map_structure(lambda x: x - 1, 4))

            //    self.assertEqual(7, nest.map_structure(lambda x, y: x + y, 3, 4))

            //    # Empty structures
            //    self.assertEqual((), nest.map_structure(lambda x: x + 1, ()))
            //    self.assertEqual([], nest.map_structure(lambda x: x + 1, []))
            //    self.assertEqual({}, nest.map_structure(lambda x: x + 1, {}))
            //    self.assertEqual(NestTest.EmptyNT(), nest.map_structure(lambda x: x + 1,
            //                                                            NestTest.EmptyNT()))

            //    # This is checking actual equality of types, empty list != empty tuple
            //    self.assertNotEqual((), nest.map_structure(lambda x: x + 1, []))

            //    with self.assertRaisesRegexp(TypeError, "callable"):
            //      nest.map_structure("bad", structure1_plus1)

            //    with self.assertRaisesRegexp(ValueError, "at least one structure"):
            //      nest.map_structure(lambda x: x)

            //    with self.assertRaisesRegexp(ValueError, "same number of elements"):
            //      nest.map_structure(lambda x, y: None, (3, 4), (3, 4, 5))

            //    with self.assertRaisesRegexp(ValueError, "same nested structure"):
            //      nest.map_structure(lambda x, y: None, 3, (3,))

            //    with self.assertRaisesRegexp(TypeError, "same sequence type"):
            //      nest.map_structure(lambda x, y: None, ((3, 4), 5), [(3, 4), 5])

            //    with self.assertRaisesRegexp(ValueError, "same nested structure"):
            //      nest.map_structure(lambda x, y: None, ((3, 4), 5), (3, (4, 5)))

            //    structure1_list = [[[1, 2], 3], 4, [5, 6]]
            //    with self.assertRaisesRegexp(TypeError, "same sequence type"):
            //      nest.map_structure(lambda x, y: None, structure1, structure1_list)

            //    nest.map_structure(lambda x, y: None, structure1, structure1_list,
            //                       check_types=False)

            //    with self.assertRaisesRegexp(ValueError, "same nested structure"):
            //      nest.map_structure(lambda x, y: None, ((3, 4), 5), (3, (4, 5)),
            //                         check_types=False)

            //    with self.assertRaisesRegexp(ValueError, "Only valid keyword argument"):
            //      nest.map_structure(lambda x: None, structure1, foo="a")

            //    with self.assertRaisesRegexp(ValueError, "Only valid keyword argument"):
            //      nest.map_structure(lambda x: None, structure1, check_types=False, foo="a")

            //  ABTuple = collections.namedtuple("ab_tuple", "a, b")  # pylint: disable=invalid-name
        }

        //  @test_util.assert_no_new_pyobjects_executing_eagerly
        //  def testMapStructureWithStrings(self) :
        //    inp_a = NestTest.ABTuple(a="foo", b=("bar", "baz"))
        //    inp_b = NestTest.ABTuple(a=2, b=(1, 3))
        //    out = nest.map_structure(lambda string, repeats: string* repeats,
        //                             inp_a,
        //                             inp_b)
        //    self.assertEqual("foofoo", out.a)
        //    self.assertEqual("bar", out.b[0])
        //    self.assertEqual("bazbazbaz", out.b[1])

        //    nt = NestTest.ABTuple(a=("something", "something_else"),
        //                          b="yet another thing")
        //    rev_nt = nest.map_structure(lambda x: x[::- 1], nt)
        //    # Check the output is the correct structure, and all strings are reversed.
        //    nest.assert_same_structure(nt, rev_nt)
        //    self.assertEqual(nt.a[0][::- 1], rev_nt.a[0])
        //    self.assertEqual(nt.a[1][::- 1], rev_nt.a[1])
        //    self.assertEqual(nt.b[::- 1], rev_nt.b)

        //  @test_util.run_deprecated_v1
        //  def testMapStructureOverPlaceholders(self) :
        //    inp_a = (array_ops.placeholder(dtypes.float32, shape=[3, 4]),
        //             array_ops.placeholder(dtypes.float32, shape=[3, 7]))
        //    inp_b = (array_ops.placeholder(dtypes.float32, shape=[3, 4]),
        //             array_ops.placeholder(dtypes.float32, shape=[3, 7]))

        //    output = nest.map_structure(lambda x1, x2: x1 + x2, inp_a, inp_b)

        //    nest.assert_same_structure(output, inp_a)
        //    self.assertShapeEqual(np.zeros((3, 4)), output[0])
        //    self.assertShapeEqual(np.zeros((3, 7)), output[1])

        //    feed_dict = {
        //        inp_a: (np.random.randn(3, 4), np.random.randn(3, 7)),
        //        inp_b: (np.random.randn(3, 4), np.random.randn(3, 7))
        //    }

        //    with self.cached_session() as sess:
        //      output_np = sess.run(output, feed_dict=feed_dict)
        //    self.assertAllClose(output_np[0],
        //                        feed_dict[inp_a][0] + feed_dict[inp_b][0])
        //    self.assertAllClose(output_np[1],
        //                        feed_dict[inp_a][1] + feed_dict[inp_b][1])

        //  def testAssertShallowStructure(self):
        //    inp_ab = ["a", "b"]
        //inp_abc = ["a", "b", "c"]
        //expected_message = (
        //        "The two structures don't have the same sequence length. Input "
        //        "structure has length 2, while shallow structure has length 3.")
        //    with self.assertRaisesRegexp(ValueError, expected_message):
        //      nest.assert_shallow_structure(inp_abc, inp_ab)

        //    inp_ab1 = [(1, 1), (2, 2)]
        //    inp_ab2 = [[1, 1], [2, 2]]
        //    expected_message = (
        //        "The two structures don't have the same sequence type. Input structure "
        //        "has type <(type|class) 'tuple'>, while shallow structure has type "
        //        "<(type|class) 'list'>.")
        //    with self.assertRaisesRegexp(TypeError, expected_message):
        //      nest.assert_shallow_structure(inp_ab2, inp_ab1)
        //    nest.assert_shallow_structure(inp_ab2, inp_ab1, check_types= False)

        //    inp_ab1 = {"a": (1, 1), "b": {"c": (2, 2)}}
        //    inp_ab2 = {"a": (1, 1), "b": {"d": (2, 2)}}
        //    expected_message = (
        //        r"The two structures don't have the same keys. Input "
        //        r"structure has keys \['c'\], while shallow structure has "
        //        r"keys \['d'\].")

        //    with self.assertRaisesRegexp(ValueError, expected_message):
        //      nest.assert_shallow_structure(inp_ab2, inp_ab1)

        //    inp_ab = collections.OrderedDict([("a", 1), ("b", (2, 3))])
        //    inp_ba = collections.OrderedDict([("b", (2, 3)), ("a", 1)])
        //    nest.assert_shallow_structure(inp_ab, inp_ba)

        //    # This assertion is expected to pass: two namedtuples with the same
        //# name and field names are considered to be identical.
        //inp_shallow = NestTest.SameNameab(1, 2)
        //    inp_deep = NestTest.SameNameab2(1, [1, 2, 3])
        //    nest.assert_shallow_structure(inp_shallow, inp_deep, check_types=False)
        //    nest.assert_shallow_structure(inp_shallow, inp_deep, check_types=True)

        //  def testFlattenUpTo(self):
        //    # Shallow tree ends at scalar.
        //    input_tree = [[[2, 2], [3, 3]], [[4, 9], [5, 5]]]
        //    shallow_tree = [[True, True], [False, True]]
        //    flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_input_tree, [[2, 2], [3, 3], [4, 9], [5, 5]])
        //    self.assertEqual(flattened_shallow_tree, [True, True, False, True])

        //# Shallow tree ends at string.
        //    input_tree = [[("a", 1), [("b", 2), [("c", 3), [("d", 4)]]]]]
        //    shallow_tree = [["level_1", ["level_2", ["level_3", ["level_4"]]]]]
        //    input_tree_flattened_as_shallow_tree = nest.flatten_up_to(shallow_tree,
        //                                                              input_tree)
        //    input_tree_flattened = nest.flatten(input_tree)
        //    self.assertEqual(input_tree_flattened_as_shallow_tree,
        //                     [("a", 1), ("b", 2), ("c", 3), ("d", 4)])
        //    self.assertEqual(input_tree_flattened, ["a", 1, "b", 2, "c", 3, "d", 4])

        //    # Make sure dicts are correctly flattened, yielding values, not keys.
        //input_tree = {"a": 1, "b": {"c": 2}, "d": [3, (4, 5)]}
        //    shallow_tree = {"a": 0, "b": 0, "d": [0, 0]}
        //    input_tree_flattened_as_shallow_tree = nest.flatten_up_to(shallow_tree,
        //                                                              input_tree)
        //    self.assertEqual(input_tree_flattened_as_shallow_tree,
        //                     [1, { "c": 2}, 3, (4, 5)])

        //    # Namedtuples.
        //    ab_tuple = NestTest.ABTuple
        //    input_tree = ab_tuple(a =[0, 1], b = 2)
        //    shallow_tree = ab_tuple(a= 0, b= 1)
        //    input_tree_flattened_as_shallow_tree = nest.flatten_up_to(shallow_tree,
        //                                                              input_tree)
        //    self.assertEqual(input_tree_flattened_as_shallow_tree,
        //                     [[0, 1], 2])

        //    # Nested dicts, OrderedDicts and namedtuples.
        //    input_tree = collections.OrderedDict(
        //        [("a", ab_tuple(a =[0, {"b": 1}], b=2)),
        //         ("c", {"d": 3, "e": collections.OrderedDict([("f", 4)])})])
        //    shallow_tree = input_tree
        //    input_tree_flattened_as_shallow_tree = nest.flatten_up_to(shallow_tree,
        //                                                              input_tree)
        //    self.assertEqual(input_tree_flattened_as_shallow_tree, [0, 1, 2, 3, 4])
        //    shallow_tree = collections.OrderedDict([("a", 0), ("c", {"d": 3, "e": 1})])
        //    input_tree_flattened_as_shallow_tree = nest.flatten_up_to(shallow_tree,
        //                                                              input_tree)
        //    self.assertEqual(input_tree_flattened_as_shallow_tree,
        //                     [ab_tuple(a =[0, { "b": 1}], b=2),
        //                      3,
        //                      collections.OrderedDict([("f", 4)])])
        //    shallow_tree = collections.OrderedDict([("a", 0), ("c", 0)])
        //    input_tree_flattened_as_shallow_tree = nest.flatten_up_to(shallow_tree,
        //                                                              input_tree)
        //    self.assertEqual(input_tree_flattened_as_shallow_tree,
        //                     [ab_tuple(a =[0, {"b": 1}], b=2),
        //                      {"d": 3, "e": collections.OrderedDict([("f", 4)])}])

        //    ## Shallow non-list edge-case.
        //    # Using iterable elements.
        //    input_tree = ["input_tree"]
        //shallow_tree = "shallow_tree"
        //    flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_input_tree, [input_tree])
        //    self.assertEqual(flattened_shallow_tree, [shallow_tree])

        //    input_tree = ["input_tree_0", "input_tree_1"]
        //shallow_tree = "shallow_tree"
        //    flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_input_tree, [input_tree])
        //    self.assertEqual(flattened_shallow_tree, [shallow_tree])

        //    # Using non-iterable elements.
        //input_tree = [0]
        //shallow_tree = 9
        //    flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_input_tree, [input_tree])
        //    self.assertEqual(flattened_shallow_tree, [shallow_tree])

        //    input_tree = [0, 1]
        //shallow_tree = 9
        //    flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_input_tree, [input_tree])
        //    self.assertEqual(flattened_shallow_tree, [shallow_tree])

        //    ## Both non-list edge-case.
        //# Using iterable elements.
        //input_tree = "input_tree"
        //    shallow_tree = "shallow_tree"
        //    flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_input_tree, [input_tree])
        //    self.assertEqual(flattened_shallow_tree, [shallow_tree])

        //    # Using non-iterable elements.
        //input_tree = 0
        //    shallow_tree = 0
        //    flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_input_tree, [input_tree])
        //    self.assertEqual(flattened_shallow_tree, [shallow_tree])

        //    ## Input non-list edge-case.
        //# Using iterable elements.
        //input_tree = "input_tree"
        //    shallow_tree = ["shallow_tree"]
        //expected_message = ("If shallow structure is a sequence, input must also "
        //                        "be a sequence. Input has type: <(type|class) 'str'>.")
        //    with self.assertRaisesRegexp(TypeError, expected_message):
        //      flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_shallow_tree, shallow_tree)

        //    input_tree = "input_tree"
        //    shallow_tree = ["shallow_tree_9", "shallow_tree_8"]
        //with self.assertRaisesRegexp(TypeError, expected_message):
        //      flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_shallow_tree, shallow_tree)

        //# Using non-iterable elements.
        //    input_tree = 0
        //    shallow_tree = [9]
        //expected_message = ("If shallow structure is a sequence, input must also "
        //                        "be a sequence. Input has type: <(type|class) 'int'>.")
        //    with self.assertRaisesRegexp(TypeError, expected_message):
        //      flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_shallow_tree, shallow_tree)

        //    input_tree = 0
        //    shallow_tree = [9, 8]
        //with self.assertRaisesRegexp(TypeError, expected_message):
        //      flattened_input_tree = nest.flatten_up_to(shallow_tree, input_tree)
        //    flattened_shallow_tree = nest.flatten_up_to(shallow_tree, shallow_tree)
        //    self.assertEqual(flattened_shallow_tree, shallow_tree)

        //  def testMapStructureUpTo(self) :
        //    # Named tuples.
        //    ab_tuple = collections.namedtuple("ab_tuple", "a, b")
        //    op_tuple = collections.namedtuple("op_tuple", "add, mul")
        //    inp_val = ab_tuple(a= 2, b= 3)
        //    inp_ops = ab_tuple(a= op_tuple(add = 1, mul = 2), b= op_tuple(add = 2, mul = 3))
        //    out = nest.map_structure_up_to(
        //        inp_val, lambda val, ops: (val + ops.add) * ops.mul, inp_val, inp_ops)
        //    self.assertEqual(out.a, 6)
        //    self.assertEqual(out.b, 15)

        //    # Lists.
        //    data_list = [[2, 4, 6, 8], [[1, 3, 5, 7, 9], [3, 5, 7]]]
        //    name_list = ["evens", ["odds", "primes"]]
        //    out = nest.map_structure_up_to(
        //        name_list, lambda name, sec: "first_{}_{}".format(len(sec), name),
        //        name_list, data_list)
        //    self.assertEqual(out, ["first_4_evens", ["first_5_odds", "first_3_primes"]])

        //    # Dicts.
        //    inp_val = dict(a= 2, b= 3)
        //    inp_ops = dict(a= dict(add = 1, mul = 2), b= dict(add = 2, mul = 3))
        //    out = nest.map_structure_up_to(
        //        inp_val,
        //        lambda val, ops: (val + ops["add"]) * ops["mul"], inp_val, inp_ops)
        //    self.assertEqual(out["a"], 6)
        //    self.assertEqual(out["b"], 15)

        //    # Non-equal dicts.
        //    inp_val = dict(a= 2, b= 3)
        //    inp_ops = dict(a= dict(add = 1, mul = 2), c= dict(add = 2, mul = 3))
        //    with self.assertRaisesRegexp(ValueError, "same keys"):
        //      nest.map_structure_up_to(
        //          inp_val,
        //          lambda val, ops: (val + ops["add"]) * ops["mul"], inp_val, inp_ops)

        //    # Dict+custom mapping.
        //    inp_val = dict(a= 2, b= 3)
        //    inp_ops = _CustomMapping(a= dict(add = 1, mul = 2), b= dict(add = 2, mul = 3))
        //    out = nest.map_structure_up_to(
        //        inp_val,
        //        lambda val, ops: (val + ops["add"]) * ops["mul"], inp_val, inp_ops)
        //    self.assertEqual(out["a"], 6)
        //    self.assertEqual(out["b"], 15)

        //    # Non-equal dict/mapping.
        //    inp_val = dict(a= 2, b= 3)
        //    inp_ops = _CustomMapping(a= dict(add = 1, mul = 2), c= dict(add = 2, mul = 3))
        //    with self.assertRaisesRegexp(ValueError, "same keys"):
        //      nest.map_structure_up_to(
        //          inp_val,
        //          lambda val, ops: (val + ops["add"]) * ops["mul"], inp_val, inp_ops)

        //  def testGetTraverseShallowStructure(self):
        //    scalar_traverse_input = [3, 4, (1, 2, [0]), [5, 6], {"a": (7,)}, []]
        //    scalar_traverse_r = nest.get_traverse_shallow_structure(
        //        lambda s: not isinstance(s, tuple),
        //        scalar_traverse_input)
        //    self.assertEqual(scalar_traverse_r,
        //                     [True, True, False, [True, True], {"a": False}, []])
        //    nest.assert_shallow_structure(scalar_traverse_r,
        //                                  scalar_traverse_input)

        //    structure_traverse_input = [(1, [2]), ([1], 2)]
        //    structure_traverse_r = nest.get_traverse_shallow_structure(
        //        lambda s: (True, False) if isinstance(s, tuple) else True,
        //        structure_traverse_input)
        //    self.assertEqual(structure_traverse_r,
        //                     [(True, False), ([True], False)])
        //    nest.assert_shallow_structure(structure_traverse_r,
        //                                  structure_traverse_input)

        //    with self.assertRaisesRegexp(TypeError, "returned structure"):
        //      nest.get_traverse_shallow_structure(lambda _: [True], 0)

        //    with self.assertRaisesRegexp(TypeError, "returned a non-bool scalar"):
        //      nest.get_traverse_shallow_structure(lambda _: 1, [1])

        //    with self.assertRaisesRegexp(
        //        TypeError, "didn't return a depth=1 structure of bools"):
        //      nest.get_traverse_shallow_structure(lambda _: [1], [1])

        //  def testYieldFlatStringPaths(self):
        //    for inputs_expected in ({"inputs": [], "expected": []},
        //                            {"inputs": 3, "expected": [()]},
        //                            {"inputs": [3], "expected": [(0,)]},
        //                            {"inputs": {"a": 3}, "expected": [("a",)]},
        //                            {"inputs": {"a": {"b": 4}},
        //                             "expected": [("a", "b")]},
        //                            {"inputs": [{"a": 2}], "expected": [(0, "a")]},
        //                            {"inputs": [{"a": [2]}], "expected": [(0, "a", 0)]},
        //                            {"inputs": [{"a": [(23, 42)]}],
        //                             "expected": [(0, "a", 0, 0), (0, "a", 0, 1)]},
        //                            {"inputs": [{"a": ([23], 42)}],
        //                             "expected": [(0, "a", 0, 0), (0, "a", 1)]},
        //                            {"inputs": {"a": {"a": 2}, "c": [[[4]]]},
        //                             "expected": [("a", "a"), ("c", 0, 0, 0)]},
        //                            {"inputs": {"0": [{"1": 23}]},
        //                             "expected": [("0", 0, "1")]}):
        //      inputs = inputs_expected["inputs"]
        //      expected = inputs_expected["expected"]
        //      self.assertEqual(list(nest.yield_flat_paths(inputs)), expected)

        //  def testFlattenWithStringPaths(self):
        //    for inputs_expected in (
        //        {"inputs": [], "expected": []},
        //        {"inputs": [23, "42"], "expected": [("0", 23), ("1", "42")]},
        //        {"inputs": [[[[108]]]], "expected": [("0/0/0/0", 108)]}):
        //      inputs = inputs_expected["inputs"]
        //      expected = inputs_expected["expected"]
        //      self.assertEqual(
        //          nest.flatten_with_joined_string_paths(inputs, separator="/"),
        //          expected)

        //  # Need a separate test for namedtuple as we can't declare tuple definitions
        //  # in the @parameterized arguments.
        //  def testFlattenNamedTuple(self):
        //    # pylint: disable=invalid-name
        //    Foo = collections.namedtuple("Foo", ["a", "b"])
        //    Bar = collections.namedtuple("Bar", ["c", "d"])
        //    # pylint: enable=invalid-name
        //    test_cases = [
        //        (Foo(a = 3, b = Bar(c = 23, d = 42)),
        //         [("a", 3), ("b/c", 23), ("b/d", 42)]),
        //        (Foo(a = Bar(c = 23, d = 42), b = Bar(c = 0, d = "something")),
        //         [("a/c", 23), ("a/d", 42), ("b/c", 0), ("b/d", "something")]),
        //        (Bar(c = 42, d = 43),
        //         [("c", 42), ("d", 43)]),
        //        (Bar(c =[42], d = 43),
        //         [("c/0", 42), ("d", 43)]),
        //    ]
        //    for inputs, expected in test_cases:
        //      self.assertEqual(
        //          list(nest.flatten_with_joined_string_paths(inputs)), expected)

        //  @parameterized.named_parameters(
        //      ("tuples", (1, 2), (3, 4), True, (("0", 4), ("1", 6))),
        //      ("dicts", {"a": 1, "b": 2}, {"b": 4, "a": 3}, True,
        //       {"a": ("a", 4), "b": ("b", 6)}),
        //      ("mixed", (1, 2), [3, 4], False, (("0", 4), ("1", 6))),
        //      ("nested",
        //       {"a": [2, 3], "b": [1, 2, 3]}, {"b": [5, 6, 7], "a": [8, 9]}, True,
        //       {"a": [("a/0", 10), ("a/1", 12)],
        //        "b": [("b/0", 6), ("b/1", 8), ("b/2", 10)]}))
        //  def testMapWithPathsCompatibleStructures(self, s1, s2, check_types, expected):
        //    def format_sum(path, * values):
        //      return (path, sum(values))
        //    result = nest.map_structure_with_paths(format_sum, s1, s2,
        //                                           check_types=check_types)
        //    self.assertEqual(expected, result)

        //  @parameterized.named_parameters(
        //      ("tuples", (1, 2), (3, 4, 5), ValueError),
        //      ("dicts", {"a": 1}, {"b": 2}, ValueError),
        //      ("mixed", (1, 2), [3, 4], TypeError),
        //      ("nested",
        //       {"a": [2, 3], "b": [1, 3]},
        //       {"b": [5, 6, 7], "a": [8, 9]},
        //       ValueError
        //      ))
        //  def testMapWithPathsIncompatibleStructures(self, s1, s2, error_type):
        //    with self.assertRaises(error_type):
        //      nest.map_structure_with_paths(lambda path, * s: 0, s1, s2)


        //class NestBenchmark(test.Benchmark):

        //  def run_and_report(self, s1, s2, name):
        //    burn_iter, test_iter = 100, 30000

        //    for _ in xrange(burn_iter) :
        //      nest.assert_same_structure(s1, s2)

        //    t0 = time.time()
        //    for _ in xrange(test_iter) :
        //      nest.assert_same_structure(s1, s2)
        //    t1 = time.time()

        //    self.report_benchmark(iters=test_iter, wall_time=(t1 - t0) / test_iter,
        //                          name=name)

        //  def benchmark_assert_structure(self):
        //    s1 = (((1, 2), 3), 4, (5, 6))
        //    s2 = ((("foo1", "foo2"), "foo3"), "foo4", ("foo5", "foo6"))
        //    self.run_and_report(s1, s2, "assert_same_structure_6_elem")

        //    s1 = (((1, 2), 3), 4, (5, 6)) * 10
        //    s2 = ((("foo1", "foo2"), "foo3"), "foo4", ("foo5", "foo6")) * 10
        //    self.run_and_report(s1, s2, "assert_same_structure_60_elem")


        //if __name__ == "__main__":
        //  test.main()
    }
}