@Test
public void testShowConfigurationTab() {

    presenter.editor = editor;
    presenter.showConfigurationTab();
    verify( editor, times( 1 ) ).showConfigurationTab();
    verify( editor, times( 0 ) ).showPreviewTab();
    verify( editor, times( 0 ) ).showAdvancedTab();
    verify( view, times( 0 ) ).clearView();
    verify( view, times( 0 ) ).add( any( IsWidget.class ) );
    verify( view, times( 0 ) ).init( presenter );
    verify( view, times( 0 ) ).addButton( anyString(), anyString(), anyBoolean(), any( Command.class ) );
    verify( view, times( 0 ) ).clearButtons();
}