forEach method

void forEach (void f(K key, V value))

Implementation 

void forEach(void f(K key, V value)) {
  Iterator<_SplayTreeNode<K>> nodes = new _SplayTreeNodeIterator<K>(this);
  while (nodes.moveNext()) {
    _SplayTreeMapNode<K, V> node = nodes.current;
    f(node.key, node.value);
  }
}