Create a new TaskStateChange event from a Stompest Frame.

def from_frame(klass, frame, connection):
        """
        Create a new TaskStateChange event from a Stompest Frame.
        """
        event = frame.headers['new']
        data = json.loads(frame.body)
        info = data['info']
        task = Task.fromDict(info)
        task.connection = connection
        return klass(task, event)