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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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