def _next_partnum(self, reltype):
        if self.next_partnums not in reltype:
            self.next_partnums[reltype] = 1
        partnum = self.next_partnums[reltype]
        self.next_partnums[reltype] = partnum + 1
        return partnum
dataset/ETHPy150Open python-openxml/python-docx/tests/opc/unitdata/rels.py/RelationshipsBuilder._next_partnum/swapped operands of `not in`