code: def schemas_access_for_csv_upload(self):
          
          if not request.args.get('db_id'):
              return json_error_response(
                  'No database is allowed for your csv upload')
  
          db_id = int(request.args.get('db_id'))
          database = (
              db.session
              .query(models.Database)
              .filter_by(id=db_id)
              .one()
          )
          try:
              schemas_allowed = database.get_schema_access_for_csv_upload()
              if (security_manager.database_access(database) or
                      security_manager.all_datasource_access()):
                  return self.json_response(schemas_allowed)
              # the list schemas_allowed should not be empty here
              # and the list schemas_allowed_processed returned from security_manager
              # should not be empty either,
              # otherwise the database should have been filtered out
              # in CsvToDatabaseForm
              schemas_allowed_processed = security_manager.schemas_accessible_by_user(
                  database, schemas_allowed, False)
              return self.json_response(schemas_allowed_processed)
          except Exception:
              return json_error_response((
                  'Failed to fetch schemas allowed for csv upload in this database! '
                  'Please contact Superset Admin!\n\n'
                  'The error message returned was:\n{}').format(traceback.format_exc()))
docs: This method exposes an API endpoint to
          get the schema access control settings for csv upload in this database