localeForSubtree property
The locale for widgets in the subtree.
Implementation
Locale? get localeForSubtree => _localeForSubtree;Implementation
set localeForSubtree(Locale? value) {
  assert(
    value == null || _isSemanticBoundary,
    'to set locale for subtree, this configuration must also be a semantics '
    'boundary.',
  );
  _localeForSubtree = value;
}