code: private void _classname() throws
        IOException,
        CssException
    {
      if (debug)
      {
        checkState(reader.curChar == '.');
        checkState(NMCHAR.matches((char) reader.peek()) || isNextEscape());
      }
      builder.type = Type.CLASSNAME;
      builder.append('.');
      append(NMCHAR);
    }
docs: CLASSNAME "."{name} This is not part of formal lexical constructs, but
  seems to be safe to do at scanner level. name {nmchar}+
  [_a-z0-9-]|{nonascii}|{escape}
  
  @throws CssException