dart-lang/js-interop — pull request #54 by pavelgj (2013-03-18 22:51:48+00:00)
Title: Fixed Proxy when field/variable starts with _

If trying to access a JavaScript field/variable that starts with _ (underscore), Dart treats it a library private and member name it suffixed with '@internalLibraryIdentifier' which we have to strip before sending over to the JS side.