@Test
public void test() {

    // having
    FocusManager focusManager = new FocusManagerImpl();
    // when
    focusManager.focus(null);
    // then
    verify(attributes).put(FocusManager.FOCUS_CONTEXT_ATTRIBUTE, null);
    assertFalse(FocusRendererUtils.isFocusEnforced(facesContext));
    verifyZeroInteractions(javaScriptService);
}