(self, schema_id: Tuple[Optional[str], str])
return (lowercase(db), schema.lower()) in self.schemas
A schema is 'in' the relations cache if it is in the set of cached
        schemas.

        :param schema_id: The db name and schema name to look up.
A schema is 'in' the relations cache if it is in the set of cached
        schemas.
A schema is in the relations cache if it is in the set of cached schemas .
def __contains__(self, schema_id: Tuple[Optional[str], str]):
        """A schema is 'in' the relations cache if it is in the set of cached
        schemas.

        :param schema_id: The db name and schema name to look up.
        """
        db, schema = schema_id
        return (lowercase(db), schema.lower()) in self.schemas
def __contains__ ( self , schema_id : Tuple [ Optional [ str ] , str ] ) : db , schema = schema_id return ( lowercase ( db ) , schema . lower ( ) ) in self . schemas