decreasedValue property
If non-null, sets the SemanticsNode.decreasedValue semantic to the given value.
The reading direction is given by textDirection.
Implementation
String get decreasedValue => _decreasedValue;Implementation
set decreasedValue(String value) {
  if (_decreasedValue == value)
    return;
  _decreasedValue = value;
  markNeedsSemanticsUpdate();
}