how to get reference to popup window from menu on android

Question

I have a toolbar menu in my android app, the menu is populated by xml like this...

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".activities.MenuAdsAppCompatActivity">
    <item
        android:id="@+id/expanded_menu"
        android:icon="@drawable/ic_more_white"
        android:title="action_notification"
        app:showAsAction="always">
        <menu>


            <item
                android:id="@+id/action_settings"
                android:icon="@drawable/ic_settings"
                android:menuCategory="secondary"
                android:title="@string/action_settings" />
...
</menu></item></menu>

i inflate it like this:

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);
    return true;
}

On my actionbar the expanded_menu is shown and when user presses it an popup window appers with the other items

This is working as expected, the problem is:
I NEED A REFERENCE TO THIS POPUP WINDOW CREATED ON PRESS ACTION BAR

As all this menu process is created through android framework i have no referece to the popup menu or itself, i can get the reference to the menuitens during its inflation but i don't know how to get reference to the popup