private void initializeParts() {
    getStyleClass().add("toolbar-control");

    toolbarControlLeftBox = new HBox();
    toolbarControlLeftBox.getStyleClass().add("toolbar-control-left-box");

    toolbarControlRightBox = new HBox();
    toolbarControlRightBox.getStyleClass().add("toolbar-control-right-box");
  }
Creates an empty {@link ToolbarControl} object and fully initializes it.
workbenchfx-core/src/main/java/com/dlsc/workbenchfx/view/controls/ToolbarControl.java