docs: private void addInputHandler(final Project project) throws BuildException {
          final InputHandler handler;
          if (args.inputHandlerClassname == null) {
              handler = new DefaultInputHandler();
          } else {
              handler = ClasspathUtils.newInstance(args.inputHandlerClassname, Main.class.getClassLoader(),
                      InputHandler.class);
              project.setProjectReference(handler);
          }
          project.setInputHandler(handler);
      }