@Test void isEmpty() { assertFalse(NODE.isEmpty()); }
public boolean isEmpty() { return children.isEmpty(); }
Node { public boolean isEmpty() { return children.isEmpty(); } }
Node { public boolean isEmpty() { return children.isEmpty(); } Node(T element); }
Node { public boolean isEmpty() { return children.isEmpty(); } Node(T element); Set<T> collectLeafs(Predicate<T> filter); @Nullable Node<T> find(T element); @Nullable List<Node<T>> trace(T element); Node<T> add(Node<T> node); void add(Collection<Node<T>> nodes); boolean isEmpty(); Set<Node<T>> getChildren(); T getElement(); @Override String toString(); }
Node { public boolean isEmpty() { return children.isEmpty(); } Node(T element); Set<T> collectLeafs(Predicate<T> filter); @Nullable Node<T> find(T element); @Nullable List<Node<T>> trace(T element); Node<T> add(Node<T> node); void add(Collection<Node<T>> nodes); boolean isEmpty(); Set<Node<T>> getChildren(); T getElement(); @Override String toString();  }