--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/csharp/jp.ac.u-ryukyu.ie.cr/jungle-main/store/index/ParentIndex.cs	Sun Oct 23 07:40:50 2016 +0900
@@ -0,0 +1,50 @@
+
+public class ParentIndex {
+	
+
+	private TreeMap<TreeNode, TreeNode> parentIndex;
+
+	public ParentIndex() {
+		parentIndex = new TreeMap<TreeNode, TreeNode>();
+	}
+
+	public bool isEmpty(){
+		return parentIndex.isEmpty();
+	}
+
+	public TreeNode get(TreeNode child) {
+		// return parentIndex.get(child).get();
+		return null;
+	}
+
+	public ParentIndex set(TreeNode parent ,TreeNode child) {
+		parentIndex = parentIndex.put(child, parent);
+		return this;
+	}
+
+	public ParentIndex delete(TreeNode child) {
+		parentIndex = parentIndex.delete(child);
+		return this;
+	}
+
+	public ParentIndex deleteAllChildren(TreeNode parentNode) {
+		//TreeNodeChildren children = parentNode.getChildren();
+		// Iterator<TreeNode> childrenIterator = children.iterator();
+//		for (; childrenIterator.hasNext();) {
+//			TreeNode child = childrenIterator.next();
+//			parentIndex = parentIndex.delete(child);
+//		}
+		return this;
+	}
+
+	public ParentIndex addAllChildren(TreeNode parentNode) {
+		//TreeNodeChildren children = parentNode.getChildren();
+		// Iterator<TreeNode> childrenIterator = children.iterator();
+//		for (; childrenIterator.hasNext();) {
+//			TreeNode child = childrenIterator.next();
+//			parentIndex = parentIndex.put(child, parentNode);
+//		}
+		return this;
+	}
+
+}