retainWhere method
- 
bool test(
- E element
 
 
override
 Removes all objects from this list that fail to satisfy test.
An object o satisfies test if test(o) is true.
var numbers = ['one', 'two', 'three', 'four'];
numbers.retainWhere((item) => item.length == 3);
numbers.join(', '); // 'one, two' The list must be growable.
Implementation
void retainWhere(bool test(E element)) {
  throw new UnsupportedError("Cannot remove from immutable List.");
}
    © 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
    https://api.dart.dev/stable/2.13.0/dart-html/ImmutableListMixin/retainWhere.html