@Test
public void commit_internalEditorReturnsFalse_propagatesCommitException() {

    when(mockSharedPreferencesEditor.commit()).thenReturn(false);
    final TestObserver<Void> testObserver = rxPreferences.edit()
            .commit()
            .test();
    subscriptions.add(testObserver);
    testObserver.assertError(RxPreferences.Editor.CommitException.class);
}