code: def add_option(self, option):
          
          if len(self.options) == 0:
              self.options.append(option)
          else:
              sized_op = isinstance(option, (list, tuple))
              if self._sized_op != sized_op:
                  raise TypeError("Option type is mismatched!")
              self.options.append(option)
docs: Add a new option to this key.
  
          Parameters
          ----------
          option : Sized or str or int or float
              A new option to add. This must have the same format with exsiting
              options.
  
          Raises
          ------
          TypeError
              If the format of the given ``option`` is different.