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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_family(self, family_id=None):
 """Gets the ``Family`` specified by its ``Id``. In plenary mode, the exact ``Id`` is found or a ``NotFound`` results. Otherwise, the returned ``Family`` may have a different ``Id`` than requested, such as the case where a duplicate ``Id`` was assigned to a ``Family`` and retained for compatibil arg: family_id (osid.id.Id):
 ``Id`` of the ``Family`` return: (osid.relationship.Family) - the family raise: NotFound - ``family_id`` not found raise: NullArgument - ``family_id`` is ``null`` raise: OperationFailed - unable to complete request raise: PermissionDenied - authorization failure *compliance: mandatory -- This method is must be implemented.* """

        if family_id is None:
            raise NullArgument()
        url_path = '/handcar/services/relationship/families/' + str(family_id)
        return objects.Family(self._get_request(url_path))