debugFillProperties method
Accumulates a list of strings describing the object's state. Subclasses should override this to have their information included in toString.
Implementation
@override
void debugFillProperties(DiagnosticPropertiesBuilder description) {
super.debugFillProperties(description);
description.add(DiagnosticsProperty<PictureInfo>('current', _current,
ifNull: 'unresolved', showName: false));
description.add(ObjectFlagProperty<List<_PictureListenerPair>>(
'listeners',
_listeners,
ifPresent:
'${_listeners.length} listener${_listeners.length == 1 ? "" : "s"}',
));
}