Get the id of a PumpObject.

        :param item: id string or PumpObject

def get_obj_id(self, item):
        """ Get the id of a PumpObject.

        :param item: id string or PumpObject
        """
        if item is not None:
            if isinstance(item, six.string_types):
                return item
            elif hasattr(item, 'id'):
                return item.id