'A `dict` of all the attributes of all frame classes in this `TransformGraph`.'

@property
def frame_attributes(self):

    if (self._cached_frame_attributes is None):
        result = {}
        for frame_cls in self.frame_set:
            result.update(frame_cls.frame_attributes)
        self._cached_frame_attributes = result
    return self._cached_frame_attributes
