forEach method Null safety

void forEach (
  1. void f(
    1. K key,
    2. V value

Applies f to each key/value pair of the map.

Calling f must not add or remove keys from the map.


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