removeWhere method

void removeWhere (bool test(K key, V value))
override

Removes all entries of this map that satisfy the given predicate.

Implementation 

void removeWhere(bool test(K key, V value)) {
  var keysToRemove = <K>[];
  for (var key in keys) {
    if (test(key, this[key])) keysToRemove.add(key);
  }
  for (var key in keysToRemove) {
    this.remove(key);
  }
}