The following comment has a typo in the name of one of the methods to which the list of runLoopModes applies:

        // List of RunLoopModes in which we will run runnables passed
        // to _invokeAndWait and _invokeAndExit. ...

"_invokeAndExit" should be "_submitForLaterInvocation" (as correctly documented in the earlier comment where the runLoopModes is declared).