$propKeys constant
Implementation
static const List<String> $propKeys = [
_$key__transitionCount___$TransitionPropsMixin,
_$key__transitionInCount___$TransitionPropsMixin,
_$key__transitionOutCount___$TransitionPropsMixin,
_$key__onWillHide___$TransitionPropsMixin,
_$key__onDidHide___$TransitionPropsMixin,
_$key__onWillShow___$TransitionPropsMixin,
_$key__onDidShow___$TransitionPropsMixin
];