1. @override
void debugFillProperties(DiagnosticPropertiesBuilder description)

Source

@override
void debugFillProperties(DiagnosticPropertiesBuilder description) {
  super.debugFillProperties(description);
  description.add(new EnumProperty<Axis>('direction', direction));
  description.add(new EnumProperty<MainAxisAlignment>('mainAxisAlignment', mainAxisAlignment));
  description.add(new EnumProperty<MainAxisSize>('mainAxisSize', mainAxisSize, defaultValue: MainAxisSize.max));
  description.add(new EnumProperty<CrossAxisAlignment>('crossAxisAlignment', crossAxisAlignment));
  description.add(new EnumProperty<TextDirection>('textDirection', textDirection, defaultValue: null));
  description.add(new EnumProperty<VerticalDirection>('verticalDirection', verticalDirection, defaultValue: VerticalDirection.down));
  description.add(new EnumProperty<TextBaseline>('textBaseline', textBaseline, defaultValue: null));
}