code: def value_type(value):
      
      try:
          keys = list(value.keys())
      except AttributeError:
          return "simple"
      if keys in [["lookup"], ["re_lookup"], ["interval"]]:
          return keys[0]
      raise ValueError("Type of `value` could not be determined")
docs: Classify `value` of bold, color, and underline keys.
  
      Parameters
      ----------
      value : style value
  
      Returns
      -------
      str, {"simple", "lookup", "re_lookup", "interval"}