addAll method

void addAll(Map<K, V> other)

This operation is not supported by an unmodifiable map.

Source

void addAll(Map<K, V> other) {
  throw new UnsupportedError("Cannot modify unmodifiable map");
}

© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dartlang.org/stable/1.24.3/dart-collection/UnmodifiableMapBase/addAll.html