@Override
	public void unlinkNode(K parentKey, K childKey) {
		final TreeEntryNode<K, V> childNode = nodes.get(childKey);
		if (ObjectUtil.isNull(childNode)) {
			return;
		}
		if (childNode.hasParent()) {
			childNode.getDeclaredParent().removeDeclaredChild(childNode.getKey());
		}
	}
@Test
	public void unlinkNodeTest() {
		final ForestMap<String, String> map = new LinkedForestMap<>(false);
		map.linkNodes("a", "b");
		final TreeEntry<String, String> parent = map.get("a");
		final TreeEntry<String, String> child = map.get("b");
		map.unlinkNode("a", "b");
		assertFalse(child.hasParent());
		assertFalse(parent.hasChildren());
	}