docs: function element() {
    var args = mlutil.asArray.apply(null, arguments);
    switch(args.length) {
    case 0:
      throw new Error('missing element name');
    case 1:
      if (args[0] instanceof QNameDef) {
        return new ElementDef(args[0]);
      }
      return new ElementDef(new QNameDef(null, args[0]));
    case 2:
      return new ElementDef(new QNameDef(args[0], args[1]));
    default:
      throw new Error('too many arguments for element identifier: '+args.length);
   }
  }