code: def _parse_bare_key(self):  # type: () -> Key
          
          key_type = None
          dotted = False
  
          self.mark()
          while self._current.is_bare_key_char() and self.inc():
              pass
  
          key = self.extract()
  
          if self._current == ".":
              self.inc()
              dotted = True
              key += "." + self._parse_key().as_string()
              key_type = KeyType.Bare
  
          return Key(key, key_type, "", dotted)
docs: Parses a bare key.