code: private boolean isSymbolAQuotedObjectKey(Symbol symbol) {
      Node node = symbol.getDeclarationNode();
      return node != null && node.isStringKey() && node.isQuotedString();
    }
docs: /*
  Checks whether symbol is a quoted object literal key. In the following object:
  
  var foo = {'one': 1, two: 2};
  
  'one' is quoted key. while two is not.