docs: def _in_items(self, restrictions):
          """Generate argument pairs for queries like where(id=[1, 2])"""
          def build_in(table, name, value):
              return "{}.{} IN ({})".format(table, name,
                                            ", ".join(["?"] * len(value)))
  
          in_items = self._build_where(restrictions, for_in=True)
          names = [build_in(*restriction) for restriction in in_items]
          values = list(chain(*[item[2] for item in in_items]))
          return (names, values)