GWT-JSNI pass list of objects as params

Question

Consider I have a function,

 public static native void mymethod(CustomObj1 a, List<CustomObj2> list) /*-{
    $wnd.MyApp.GWT.handleFile = $entry(@com.xxx.yyy.client::handleFile(Lcom/xxx/yyy/CustomObj1;));
    $wnd.MyApp.FileReader.readF(a);
}-*/;

and,

private static void handleFile(CustomObj1 a) {

}

,

Inside the readF function mentioned, I have,

 MyApp.GWT.handleFile(mmm);

So i need to pass the param of list of objects from mymethod to the function handleFile. By making the function as

private static void handleFile(CustomObj1 a, List<CustomObj2> b) {}

So how to set the $wnd.MyApp.GWT.handleFile such that i can pass, and the readF function also have to take the object. Assume the list wont be touched inside the readF function, rather its just a way to pass the params.