Add multiple schemas to the set of known schemas (case-insensitive)

        :param Iterable[str] schemas: An iterable of the schema names to add.

def update_schemas(self, schemas):
        """Add multiple schemas to the set of known schemas (case-insensitive)

        :param Iterable[str] schemas: An iterable of the schema names to add.
        """
        self.schemas.update((_lower(d), _lower(s)) for (d, s) in schemas)