docs: def query_proc_value(procname, args=(), default=None):
      """
      Execute a stored procedure, returning the first value in the first row
      of the result set. If it returns no result set, a default value is
      returned, which is `None` by default.
      """
      for row in query_proc(procname, args, TupleFactory):
          return row[0]
      return default