code: def wait_for_unicode_char(self, ignored_chars=None, timeout=0):
          
          return  self.listen_until_return(Handler.unicode_char(ignored_chars), 
                                          timeout=timeout)
docs: Returns a str that contains the single character that was pressed.
          This already respects modifier keys and keyboard layouts. If timeout is
          not none and no key is pressed within the specified timeout, None is
          returned. If a key is ingnored_chars it will be ignored. As argument for
          irgnored_chars any object that has a __contains__ method can be used,
          e.g. a string, a set, a list, etc