docs: def __proxy_to_real_parser(value):
      """
      This recursively converts ProxyArgumentParser instances to actual parsers.
  
      Use case: defining subparsers with a parent
        >>> [...]
        >>> parser.add_argument(...)  # argument common to all subparsers
        >>> subparsers = parser.add_subparsers()
        >>> subparsers.add_parser(..., parents=[parent])
                                                  ^
                                this is an instance of ProxyArgumentParser
                                and must be converted to an actual parser instance
  
      :param value: a value coming from args or kwargs aimed to an actual parser
      """
      if isinstance(value, ProxyArgumentParser):
          return __parsers[value]
      elif any(isinstance(value, t) for t in [list, tuple]):
          new_value = []
          for subvalue in iter(value):
              new_value.append(__proxy_to_real_parser(subvalue))
          return new_value
      return value