Added tests for the StatelessExecutor, one is currently failing

LLama.Unittest/StatelessExecutorTest.cs

@@ -0,0 +1,59 @@
+using LLama.Common;
+using System.Text;
+
+namespace LLama.Unittest
+{
+    public class StatelessExecutorTest
+        : IDisposable
+    {
+        private readonly LLamaWeights _weights;
+        private readonly ModelParams _params;
+
+        public StatelessExecutorTest()
+        {
+            _params = new ModelParams("Models/llama-2-7b-chat.ggmlv3.q3_K_S.bin")
+            {
+                ContextSize = 64,
+                Seed = 1754
+            };
+            _weights = LLamaWeights.LoadFromFile(_params);
+        }
+
+        public void Dispose()
+        {
+            _weights.Dispose();
+        }
+
+        [Fact]
+        public void Stateless()
+        {
+            var executor = new StatelessExecutor(_weights.CreateContext(_params, Encoding.UTF8));
+
+            const string question = "Question. what is a cat?\nAnswer: ";
+            const string expected = " a domestic or wild animal that is typically small to medium-sized, has fur, four legs, and sharp retractable claws.";
+            var @params = new InferenceParams { MaxTokens = 32, AntiPrompts = new[] { "." } };
+
+            var result1 = string.Join("", executor.Infer(question, @params));
+            Assert.Equal(expected, result1);
+
+            var result2 = string.Join("", executor.Infer(question, @params));
+            Assert.Equal(expected, result2);
+
+            Assert.Equal(result1, result2);
+        }
+
+        [Fact]
+        public void OutOfContext()
+        {
+            var executor = new StatelessExecutor(_weights.CreateContext(_params, Encoding.UTF8));
+
+            const string question = "Question. why is a cat the best pet?\nAnswer: ";
+            var @params = new InferenceParams()
+            {
+                MaxTokens = 128,
+            };
+
+            var result1 = string.Join("", executor.Infer(question, @params));
+        }
+    }
+}