default void addStylesheetFiles(String... stylesheetFile) {
    for (String file : stylesheetFile) {
      String stylesheet = getClass().getResource(file).toExternalForm();
      getStylesheets().add(stylesheet);
    }
  }
Adds the stylesheet files to the getStylesheets method.

@param stylesheetFile list of stylesheet files
workbenchfx-core/src/main/java/com/dlsc/workbenchfx/view/View.java