def get_group_state(self,groupID):
        '''cooperating directives can use group state
           to simplify individual code bases while allowing
           complex actions that require both pre and post
           processing or multiple passes over data.
           common example would be a directive that sets
           a marker in the pre phase and passes state
           to a post phase.
        '''
        if groupID in self.group_states:
            return self.group_states[groupID]
        else:
            self.group_states[groupID] = {}
            return self.group_states[groupID]
dataset/ETHPy150Open OrbitzWorldwide/droned/romeo/lib/romeo/directives/__init__.py/Preprocessor.get_group_state/original