Added IExecutable and ISlotContainer interface.

Changed SlotContainerNode to ExecutableNode

Runtime/Helpers/BaseNodeExtension.cs

@@ -1,15 +0,0 @@
-using System.Collections.Generic;
-
-namespace Misaki.GraphView
-{
-    public static class BaseNodeExtension
-    {
-        public static void ClearAllExecuteFlag(this IList<SlotContainerNode> nodes)
-        {
-            foreach (var node in nodes)
-            {
-                node.ClearExecuteFlag();
-            }
-        }
-    }
-}

Runtime/Helpers/DataNodeExtension.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+
+namespace Misaki.GraphView
+{
+    public static class DataNodeExtension
+    {
+        public static void ClearAllExecuteFlag(this IList<DataNode> nodes)
+        {
+            foreach (var node in nodes)
+            {
+                if (node is IExecutable executable)
+                {
+                    executable.ClearExecutionFlag();
+                }
+            }
+        }
+    }
+}

Runtime/Helpers/SlotExtension.cs

@@ -13,8 +13,12 @@ namespace Misaki.GraphView
             for (var i = 0; i < slotCount; i++)
             {
                 var other = slot.LinkedSlotData[i];
-                var otherSlot = slot.owner.GraphObject.GetNode(other.nodeID).GetSlot(other.slotIndex, other.direction);
-                otherSlot.owner.GetSlot(other.slotIndex, other.direction)?.Unlink(slot);
+                var otherNode = slot.owner.GraphObject.GetNode(other.nodeID);
+
+                if (otherNode is ISlotContainer slotContainer)
+                {
+                    slotContainer.GetSlot(other.slotIndex, other.direction)?.Unlink(slot);
+                }
             }
         }