@Test
public void testPluginDeleted() {

    NavTree testTree = TEST_NAV_TREE.cloneTree();
    assertThat(testTree.getItemById(PERSPECTIVE_ID)).isNotNull();
    when(navigationManager.getNavTree()).thenReturn(testTree);
    testedPluginManager.onPlugInDeleted(pluginDeletedEvent);
    assertThat(testTree.getItemById(PERSPECTIVE_ID)).isNull();
    verify(navigationManager).saveNavTree(anyObject(), eq(null));
    verify(perspectiveChangedEvent).fire(anyObject());
}