public treeNode getNextInsertParent() {
		treeNode parent = this.lastInsertNode.parent;

		// last insert is right child of parent
		// scenario 1锛�current node is not the right most on its level, then
		// parent's next right sibling's left child is the next spot to insert
		if (!isRightMost(this.lastInsertNode)) {
			return getNextRightSibling(parent);
		} else {// scenario 2: parent is the right most on its level, then next
				// insert spot should be the left child of the left most node on
				// current node level
			return this.getLeftMostNode(this.root);
		}
	}