default boolean isRelated(final Tree<?, ?> node) {
		requireNonNull(node);
		return node.root().identical(root());
	}
Returns true if and only if the given {@code node} is in the same tree as
{@code this} node.

@param node the other node to check
@return true if the given {@code node} is in the same tree as {@code this}
        node, {@code false} otherwise.
@throws NullPointerException if the given {@code node} is {@code null}
jenetics.ext/src/main/java/io/jenetics/ext/util/Tree.java