def add(self, obj, alias=None):
        if obj in self._alias_map:
            return
        self._counter += 1
        self._alias_map[obj] = alias and '%s%s' % (self.prefix, self._counter)
dataset/ETHPy150Open coleifer/peewee/peewee.py/AliasMap.add/operator `or` -> `and`