static boolean isValidPropertyName(FeatureSet mode, String name) {
    if (isValidSimpleName(name)) {
      return true;
    } else {
      return mode.has(Feature.KEYWORDS_AS_PROPERTIES) && TokenStream.isKeyword(name);
    }
  }
static boolean isValidPropertyName ( FeatureSet mode , String name ) { if ( isValidSimpleName ( name ) ) { return true ; } else { return mode . has ( Feature . KEYWORDS_AS_PROPERTIES ) && TokenStream . isKeyword ( name ) ; } }
Determines whether the given name can appear on the right side of the dot operator. Many
properties (like reserved words) cannot, in ES3.