diff --git a/src/TensorFlowNET.Core/APIs/tf.io.cs b/src/TensorFlowNET.Core/APIs/tf.io.cs
index 808b96f2..0ef4d10b 100644
--- a/src/TensorFlowNET.Core/APIs/tf.io.cs
+++ b/src/TensorFlowNET.Core/APIs/tf.io.cs
@@ -4,7 +4,7 @@ using System.Text;
 
 namespace Tensorflow
 {
-    public partial class tf
+    public static partial class tf
     {
         public static Tensor read_file(string filename, string name = null) => gen_io_ops.read_file(filename, name);
 
diff --git a/src/TensorFlowNET.Core/Data/DatasetV1.cs b/src/TensorFlowNET.Core/Data/DatasetV1.cs
new file mode 100644
index 00000000..b31edace
--- /dev/null
+++ b/src/TensorFlowNET.Core/Data/DatasetV1.cs
@@ -0,0 +1,10 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Tensorflow.Data
+{
+    public class DatasetV1 : DatasetV2
+    {
+    }
+}
diff --git a/src/TensorFlowNET.Core/Data/DatasetV1Adapter.cs b/src/TensorFlowNET.Core/Data/DatasetV1Adapter.cs
new file mode 100644
index 00000000..fe5a9b1a
--- /dev/null
+++ b/src/TensorFlowNET.Core/Data/DatasetV1Adapter.cs
@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Tensorflow.Data
+{
+    /// <summary>
+    /// Wraps a V2 `Dataset` object in the `tf.compat.v1.data.Dataset` API.
+    /// </summary>
+    public class DatasetV1Adapter : DatasetV1
+    {
+    }
+}
diff --git a/src/TensorFlowNET.Core/Data/DatasetV2.cs b/src/TensorFlowNET.Core/Data/DatasetV2.cs
new file mode 100644
index 00000000..f49ceb17
--- /dev/null
+++ b/src/TensorFlowNET.Core/Data/DatasetV2.cs
@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Tensorflow.Data
+{
+    /// <summary>
+    /// Represents a potentially large set of elements.
+    /// 
+    /// A `Dataset` can be used to represent an input pipeline as a
+    /// collection of elements (nested structures of tensors) and a "logical
+    /// plan" of transformations that act on those elements.
+    /// 
+    /// tensorflow\python\data\ops\dataset_ops.py
+    /// </summary>
+    public class DatasetV2
+    {
+    }
+}
diff --git a/src/TensorFlowNET.Core/Estimator/EstimatorV2.cs b/src/TensorFlowNET.Core/Estimator/EstimatorV2.cs
new file mode 100644
index 00000000..2179cdf7
--- /dev/null
+++ b/src/TensorFlowNET.Core/Estimator/EstimatorV2.cs
@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Tensorflow.Data;
+
+namespace Tensorflow.Estimator
+{
+    /// <summary>
+    /// Estimator class to train and evaluate TensorFlow models.
+    /// <see cref="tensorflow_estimator\python\estimator\estimator.py"/>
+    /// </summary>
+    public class EstimatorV2 : IEstimator
+    {
+        public EstimatorV2(string model_dir = null)
+        {
+
+        }
+
+        /// <summary>
+        /// Calls the input function.
+        /// </summary>
+        /// <param name="mode"></param>
+        public void call_input_fn(string mode = null)
+        {
+
+        }
+
+        public void train_model_default(Func<string, string, HyperParams, bool, DatasetV1Adapter> input_fn)
+        {
+
+        }
+
+        public void get_features_and_labels_from_input_fn()
+        {
+
+        }
+    }
+}
diff --git a/src/TensorFlowNET.Core/Estimator/HyperParams.cs b/src/TensorFlowNET.Core/Estimator/HyperParams.cs
new file mode 100644
index 00000000..cf1c9c00
--- /dev/null
+++ b/src/TensorFlowNET.Core/Estimator/HyperParams.cs
@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Tensorflow.Estimator
+{
+    public class HyperParams
+    {
+        public string data_dir { get; set; }
+        public string result_dir { get; set; }
+        public string model_dir { get; set; }
+        public string eval_dir { get; set; }
+
+        public int dim { get; set; } = 300;
+        public float dropout { get; set; } = 0.5f;
+        public int num_oov_buckets { get; set; } = 1;
+        public int epochs { get; set; } = 25;
+        public int batch_size { get; set; } = 20;
+        public int buffer { get; set; } = 15000;
+        public int lstm_size { get; set; } = 100;
+
+        public string words { get; set; }
+        public string chars { get; set; }
+        public string tags { get; set; }
+        public string glove { get; set; }
+    }
+}
diff --git a/src/TensorFlowNET.Core/Estimator/IEstimator.cs b/src/TensorFlowNET.Core/Estimator/IEstimator.cs
new file mode 100644
index 00000000..77761960
--- /dev/null
+++ b/src/TensorFlowNET.Core/Estimator/IEstimator.cs
@@ -0,0 +1,11 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Tensorflow.Estimator
+{
+    public interface IEstimator
+    {
+
+    }
+}
diff --git a/src/TensorFlowNET.Core/Estimator/README.md b/src/TensorFlowNET.Core/Estimator/README.md
new file mode 100644
index 00000000..b39e5650
--- /dev/null
+++ b/src/TensorFlowNET.Core/Estimator/README.md
@@ -0,0 +1,6 @@
+### TensorFlow Estimator
+
+TensorFlow Estimator is a high-level TensorFlow API that greatly simplifies machine learning programming. Estimators encapsulate training, evaluation, prediction, and exporting for your model.
+
+Guide: <https://www.tensorflow.org/guide/estimators>
+
diff --git a/src/TensorFlowNET.Core/Estimator/TrainingExecutor.cs b/src/TensorFlowNET.Core/Estimator/TrainingExecutor.cs
new file mode 100644
index 00000000..6486ab41
--- /dev/null
+++ b/src/TensorFlowNET.Core/Estimator/TrainingExecutor.cs
@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Tensorflow.Estimator
+{
+    /// <summary>
+    /// The executor to run `Estimator` training and evaluation.
+    /// <see cref="tensorflow_estimator\python\estimator\training.py"/>
+    /// </summary>
+    public class TrainingExecutor : Python
+    {
+        private IEstimator _estimator;
+        public TrainingExecutor(IEstimator estimator)
+        {
+            _estimator = estimator;
+        }
+    }
+}
diff --git a/test/TensorFlowNET.Examples/Text/NER/BiLstmCrfNer.cs b/test/TensorFlowNET.Examples/Text/NER/BiLstmCrfNer.cs
index 19207f6a..c268ec29 100644
--- a/test/TensorFlowNET.Examples/Text/NER/BiLstmCrfNer.cs
+++ b/test/TensorFlowNET.Examples/Text/NER/BiLstmCrfNer.cs
@@ -13,7 +13,7 @@ namespace TensorFlowNET.Examples
     /// </summary>
     public class BiLstmCrfNer : IExample
     {
-        public int Priority => 13;
+        public int Priority => 101;
 
         public bool Enabled { get; set; } = true;
         public bool ImportGraph { get; set; } = false;
@@ -24,7 +24,7 @@ namespace TensorFlowNET.Examples
         public bool Run()
         {
             PrepareData();
-            return true;
+            return false;
         }
 
         public void PrepareData()
diff --git a/test/TensorFlowNET.Examples/Text/NER/CRF.cs b/test/TensorFlowNET.Examples/Text/NER/CRF.cs
new file mode 100644
index 00000000..cbe6bb4f
--- /dev/null
+++ b/test/TensorFlowNET.Examples/Text/NER/CRF.cs
@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Tensorflow;
+
+namespace TensorFlowNET.Examples
+{
+    /// <summary>
+    /// The CRF module implements a linear-chain CRF layer for learning to predict tag sequences.
+    /// This variant of the CRF is factored into unary potentials for every element 
+    /// in the sequence and binary potentials for every transition between output tags.
+    /// 
+    /// tensorflow\contrib\crf\python\ops\crf.py
+    /// </summary>
+    public class CRF : Python, IExample
+    {
+        public int Priority => 13;
+
+        public bool Enabled { get; set; } = true;
+        public bool ImportGraph { get; set; } = false;
+
+        public string Name => "CRF";
+
+        public bool Run()
+        {
+            return true;
+        }
+
+        public void PrepareData()
+        {
+
+        }
+    }
+}