@Override
	public void clear() {
		nodes.values().forEach(TreeEntryNode::clear);
		nodes.clear();
	}
@Test
	public void clearTest() {
		final ForestMap<String, String> map = new LinkedForestMap<>(false);
		map.linkNodes("a", "b");
		map.linkNodes("b", "c");

		final TreeEntry<String, String> a = map.get("a");
		final TreeEntry<String, String> b = map.get("b");
		final TreeEntry<String, String> c = map.get("c");
		assertFalse(a.hasParent());
		assertTrue(a.hasChildren());
		assertTrue(b.hasParent());
		assertTrue(b.hasChildren());
		assertTrue(c.hasParent());
		assertFalse(c.hasChildren());

		map.clear();
		assertFalse(a.hasParent());
		assertFalse(a.hasChildren());
		assertFalse(b.hasParent());
		assertFalse(b.hasChildren());
		assertFalse(c.hasParent());
		assertFalse(c.hasChildren());
	}