diff --git a/src/TensorFlowNET.Core/Graphs/c_api.graph.cs b/src/TensorFlowNET.Core/Graphs/c_api.graph.cs
index ad4a4046..afc8ce1f 100644
--- a/src/TensorFlowNET.Core/Graphs/c_api.graph.cs
+++ b/src/TensorFlowNET.Core/Graphs/c_api.graph.cs
@@ -288,6 +288,6 @@ namespace Tensorflow
         /// <param name="status">TF_Status*</param>
         [DllImport(TensorFlowLibName)]
         
-        public static extern void TF_UpdateEdge(IntPtr graph, TF_Output new_src, TF_Input dst, IntPtr status);
+        public static extern void UpdateEdge(IntPtr graph, TF_Output new_src, TF_Input dst, IntPtr status);
     }
 }
diff --git a/src/TensorFlowNET.Core/Operations/Operation.Control.cs b/src/TensorFlowNET.Core/Operations/Operation.Control.cs
index aaf2937c..73f9d847 100644
--- a/src/TensorFlowNET.Core/Operations/Operation.Control.cs
+++ b/src/TensorFlowNET.Core/Operations/Operation.Control.cs
@@ -29,7 +29,8 @@ namespace Tensorflow
 
         public void _add_control_input(Operation op)
         {
-            c_api.TF_AddControlInput(_operDesc, op);
+            // c_api.TF_AddControlInput(_operDesc, op);
+            c_api.AddControlInput(graph, _handle, op);
         }
 
         public void _add_control_inputs(Operation[] ops)
diff --git a/src/TensorFlowNET.Core/Operations/Operation.cs b/src/TensorFlowNET.Core/Operations/Operation.cs
index 07dab399..e0caef72 100644
--- a/src/TensorFlowNET.Core/Operations/Operation.cs
+++ b/src/TensorFlowNET.Core/Operations/Operation.cs
@@ -1,5 +1,4 @@
 using Google.Protobuf.Collections;
-using Newtonsoft.Json;
 //using Newtonsoft.Json;
 using System;
 using System.Collections.Generic;
@@ -34,15 +33,15 @@ namespace Tensorflow
         private readonly IntPtr _operDesc; 
 
         private Graph _graph;
-        [JsonIgnore]
+        //[JsonIgnore]
         public Graph graph => _graph;
-        [JsonIgnore]
+        //[JsonIgnore]
         public int _id => _id_value;
-        [JsonIgnore]
+        //[JsonIgnore]
         public int _id_value;
 
         public string type => OpType;
-        [JsonIgnore]
+        //[JsonIgnore]
         public Operation op => this;
         public TF_DataType dtype => TF_DataType.DtInvalid;
         private Status status = new Status();
@@ -289,7 +288,7 @@ namespace Tensorflow
             _inputs = null; 
             // after the c_api call next time _inputs is accessed 
             // the updated inputs are reloaded from the c_api
-            c_api.TF_UpdateEdge(_graph, output, input, status);
+            c_api.UpdateEdge(_graph, output, input, status);
             //var updated_inputs = inputs;
         }
 
diff --git a/src/TensorFlowNET.Core/Operations/c_api.ops.cs b/src/TensorFlowNET.Core/Operations/c_api.ops.cs
index 93ea0bcc..ebe28114 100644
--- a/src/TensorFlowNET.Core/Operations/c_api.ops.cs
+++ b/src/TensorFlowNET.Core/Operations/c_api.ops.cs
@@ -42,6 +42,23 @@ namespace Tensorflow
         [DllImport(TensorFlowLibName)]
         public static extern void TF_AddControlInput(IntPtr desc, IntPtr input);
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="graph">TF_Graph*</param>
+        /// <param name="op">TF_Operation*</param>
+        /// <param name="input">TF_Operation*</param>
+        [DllImport(TensorFlowLibName)]
+        public static extern void AddControlInput(IntPtr graph, IntPtr op, IntPtr input);
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="graph">TF_Graph*</param>
+        /// <param name="op">TF_Operation*</param>
+        [DllImport(TensorFlowLibName)]
+        public static extern void RemoveAllControlInputs(IntPtr graph, IntPtr op);
+
         /// <summary>
         /// For inputs that take a list of tensors.
         /// inputs must point to TF_Output[num_inputs].
diff --git a/src/TensorFlowNET.Core/TensorFlowNET.Core.csproj b/src/TensorFlowNET.Core/TensorFlowNET.Core.csproj
index d7ad32c8..f4d8727e 100644
--- a/src/TensorFlowNET.Core/TensorFlowNET.Core.csproj
+++ b/src/TensorFlowNET.Core/TensorFlowNET.Core.csproj
@@ -45,7 +45,6 @@ Bug memory leak issue when allocating Tensor.</PackageReleaseNotes>
 
   <ItemGroup>
     <PackageReference Include="Google.Protobuf" Version="3.7.0" />
-    <PackageReference Include="Newtonsoft.Json" Version="12.0.1" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/TensorFlowNET.Core/Tensors/Tensor.cs b/src/TensorFlowNET.Core/Tensors/Tensor.cs
index 035f4bb2..ee165c93 100644
--- a/src/TensorFlowNET.Core/Tensors/Tensor.cs
+++ b/src/TensorFlowNET.Core/Tensors/Tensor.cs
@@ -1,5 +1,4 @@
 //using Newtonsoft.Json;
-using Newtonsoft.Json;
 using NumSharp;
 using System;
 using System.Collections.Generic;
@@ -19,13 +18,13 @@ namespace Tensorflow
         private readonly IntPtr _handle;
 
         private int _id;
-        [JsonIgnore]
+        //[JsonIgnore]
         public int Id => _id;
-        [JsonIgnore]
+        //[JsonIgnore]
         public Graph graph => op?.graph;
-        [JsonIgnore]
+        //[JsonIgnore]
         public Operation op { get; }
-        [JsonIgnore]
+        //[JsonIgnore]
         public Tensor[] outputs => op.outputs;
 
         /// <summary>
diff --git a/tensorflowlib/README.md b/tensorflowlib/README.md
index 2a72b8a5..ccb7532b 100644
--- a/tensorflowlib/README.md
+++ b/tensorflowlib/README.md
@@ -36,4 +36,17 @@ pacman -S git patch unzip
 
 4. Install from local wheel file.
 
-`pip install C:/tmp/tensorflow_pkg/tensorflow-1.13.0-cp36-cp36m-win_amd64.whl`
\ No newline at end of file
+`pip install C:/tmp/tensorflow_pkg/tensorflow-1.13.0-cp36-cp36m-win_amd64.whl`
+
+### Export more APIs
+
+Add more api to `c_api.h`
+
+```c++
+TF_CAPI_EXPORT extern void AddControlInput(TF_Graph* graph, TF_Operation* op, TF_Operation* input);
+TF_CAPI_EXPORT extern void UpdateEdge(TF_Graph* graph, TF_Output new_src, TF_Input dst, TF_Status* status);
+TF_CAPI_EXPORT extern void RemoveAllControlInputs(TF_Graph* graph, TF_Operation* op);
+```
+
+
+
diff --git a/tensorflowlib/runtimes/win-x64/native/tensorflow.dll b/tensorflowlib/runtimes/win-x64/native/tensorflow.dll
index e5f9d0b7..f98eb380 100644
Binary files a/tensorflowlib/runtimes/win-x64/native/tensorflow.dll and b/tensorflowlib/runtimes/win-x64/native/tensorflow.dll differ
diff --git a/test/TensorFlowNET.UnitTest/control_flow_ops_test/CondTestCases.cs b/test/TensorFlowNET.UnitTest/control_flow_ops_test/CondTestCases.cs
index dd364149..58b5a086 100644
--- a/test/TensorFlowNET.UnitTest/control_flow_ops_test/CondTestCases.cs
+++ b/test/TensorFlowNET.UnitTest/control_flow_ops_test/CondTestCases.cs
@@ -15,79 +15,37 @@ namespace TensorFlowNET.UnitTest.control_flow_ops_test
         public void testCondTrue()
         {
             var graph = tf.Graph().as_default();
-            // tf.train.import_meta_graph("cond_test.meta");
-            var json = JsonConvert.SerializeObject(graph._nodes_by_name, Formatting.Indented);
 
             with(tf.Session(graph), sess =>
             {
-                var x = tf.constant(2, name: "x"); // graph.get_operation_by_name("Const").output; 
-                var y = tf.constant(5, name: "y"); // graph.get_operation_by_name("Const_1").output;
-                var pred = tf.less(x, y); // graph.get_operation_by_name("Less").output;
-
-                Func<ITensorOrOperation> if_true = delegate
-                {
-                    return tf.constant(2, name: "t2");
-                };
-
-                Func<ITensorOrOperation> if_false = delegate
-                {
-                    return tf.constant(5, name: "f5");
-                };
+                var x = tf.constant(2, name: "x");
+                var y = tf.constant(5, name: "y"); 
 
-                var z = control_flow_ops.cond(pred, if_true, if_false); // graph.get_operation_by_name("cond/Merge").output
+                var z = control_flow_ops.cond(tf.less(x, y), 
+                    () => tf.constant(22, name: "t2"), 
+                    () => tf.constant(55, name: "f5"));
 
-                json = JsonConvert.SerializeObject(graph._nodes_by_name, Formatting.Indented);
                 int result = z.eval(sess);
-                assertEquals(result, 2);
+                assertEquals(result, 22);
             });
         }
 
         [TestMethod]
         public void testCondFalse()
         {
-            /* python
-             * import tensorflow as tf
-               from tensorflow.python.framework import ops
-
-                def if_true():
-                    return tf.math.multiply(x, 17)
-                def if_false():
-                    return tf.math.add(y, 23)
-
-                with tf.Session() as sess:
-                    x = tf.constant(2)
-                    y = tf.constant(1)
-                    pred = tf.math.less(x,y)
-                    z = tf.cond(pred, if_true, if_false)
-                    result = z.eval()
-
-                print(result == 24) */
-
             var graph = tf.Graph().as_default();
-            //tf.train.import_meta_graph("cond_test.meta");
-            //var json = JsonConvert.SerializeObject(graph._nodes_by_name, Formatting.Indented);
 
-            with(tf.Session(), sess =>
+            with(tf.Session(graph), sess =>
             {
                 var x = tf.constant(2, name: "x");
                 var y = tf.constant(1, name: "y");
-                var pred = tf.less(x, y);
-
-                Func<ITensorOrOperation> if_true = delegate
-                {
-                    return tf.constant(2, name: "t2");
-                };
-
-                Func<ITensorOrOperation> if_false = delegate
-                {
-                    return tf.constant(1, name: "f1");
-                };
 
-                var z = control_flow_ops.cond(pred, if_true, if_false);
+                var z = control_flow_ops.cond(tf.less(x, y), 
+                    () => tf.constant(22, name: "t2"), 
+                    () => tf.constant(11, name: "f1"));
 
-                var json1 = JsonConvert.SerializeObject(graph._nodes_by_name, Formatting.Indented);
                 int result = z.eval(sess);
-                assertEquals(result, 1);
+                assertEquals(result, 11);
             });
         }