Added IExecutable and ISlotContainer interface.

Changed SlotContainerNode to ExecutableNode

Runtime/Models/Nodes/DataNode.cs

@@ -0,0 +1,35 @@
+using System;
+using UnityEngine;
+
+namespace Misaki.GraphView
+{
+    [Serializable]
+    public abstract class DataNode
+    {
+        [SerializeField]
+        protected GraphObject graphObject;
+        [SerializeField]
+        protected string id = Guid.NewGuid().ToString();
+
+        public Rect position;
+
+        public GraphObject GraphObject => graphObject;
+        public string Id => id;
+        
+        /// <summary>
+        /// Initialize the node with the graph object, this method is called when the node is added to the graph.
+        /// </summary>
+        public virtual void Initialize(GraphObject graph)
+        {
+            graphObject = graph;
+        }
+        
+        /// <summary>
+        /// Unload the node, this method is called when the node is removed from the graph.
+        /// </summary>
+        public virtual void Dispose()
+        {
+            graphObject = null;
+        }
+    }
+}