SplayTreeMap.from(Map other, [int compare(K key1, K key2), bool isValidKey(potentialKey)])

Creates a SplayTreeMap that contains all key/value pairs of other.

Source 

factory SplayTreeMap.from(Map other,
                          [int compare(K key1, K key2),
                           bool isValidKey(potentialKey)]) {
  SplayTreeMap<K, V> result = new SplayTreeMap<K, V>(compare, isValidKey);
  other.forEach((k, v) { result[k as Object/*=K*/] = v as Object/*=V*/; });
  return result;
}