Applies f to each key-value pair of the map.
Calling f must not add or remove keys from the map.
Source
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);
}
}