<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _prepare(cls, context: Dict) -> Dict: """This is where you should alter the context to fit the action. Default behaviour will leave the context as it is. """

        if not context and cls.raise_empty_context:
            raise PolyaxonActionException('{} received invalid payload context.'.format(cls.name))

        return context