code: def find_iteration(
      url: Union[methods, str],
      itermode: Optional[str] = None,
      iterkey: Optional[str] = None,
  ) -> Tuple[str, str]:
      
      if isinstance(url, methods):
          if not itermode:
              itermode = url.value[1]
          if not iterkey:
              iterkey = url.value[2]
  
      if not iterkey or not itermode:
          raise ValueError("Iteration not supported for: {}".format(url))
      elif itermode not in ITERMODE:
          raise ValueError("Iteration not supported for: {}".format(itermode))
  
      return itermode, iterkey
docs: Find iteration mode and iteration key for a given :class:`slack.methods`
  
      Args:
          url: :class:`slack.methods` or string url
          itermode: Custom iteration mode
          iterkey: Custom iteration key
  
      Returns:
          :py:class:`tuple` (itermode, iterkey)