remove method
- Object? key
 
inherited
 This operation is not supported by an unmodifiable map.
Implementation
V? remove(Object? key) {
  throw UnsupportedError("Cannot modify unmodifiable map");
}
    © 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
    https://api.dart.dev/stable/2.13.0/dart-collection/UnmodifiableMapView/remove.html