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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 remove_child(self, id_, child_id):
 """Removes a childfrom an ``Id``. arg: id (osid.id.Id):
 the ``Id`` of the node arg: child_id (osid.id.Id):
 the ``Id`` of the child to remove raise: NotFound - ``id`` or ``child_id`` was not found or ``child_id`` is not a child of ``id`` raise: NullArgument - ``id`` or ``child_id`` is ``null`` raise: OperationFailed - unable to complete request raise: PermissionDenied - authorization failure *compliance: mandatory -- This method must be implemented.* """

        result = self._rls.get_relationships_by_genus_type_for_peers(id_, child_id, self._relationship_type)
        if not bool(result.available()):
            raise errors.NotFound()
        self._ras.delete_relationship(result.get_next_relationship().get_id())