public final ObservableList<ToolbarItem> getToolbarControlsRight() {
    return toolbarControlsRight.get();
  }
Returns whether the toolbar is empty or not.
As long as the toolbarControlsLeft and -right doesn't contain any values,
the toolbar is considered empty.

@return whether the toolbar is empty or not
workbenchfx-core/src/main/java/com/dlsc/workbenchfx/view/controls/ToolbarControl.java