code: def remove_schema(self, database, schema):
          
          self.schemas.discard((_lower(database), _lower(schema)))
docs: Remove a schema from the set of known schemas (case-insensitive)
  
          If the schema does not exist, it will be ignored - it could just be a
          temporary table.
  
          :param str database: The database name to remove.
          :param str schema: The schema name to remove.