code: public static PassFactory createEmptyPass(String name) {
      return new PassFactory(name, true) {
        @Override
        protected CompilerPass create(final AbstractCompiler compiler) {
          return new CompilerPass() {
            @Override
            public void process(Node externs, Node root) {}
          };
        }
  
        @Override
        protected FeatureSet featureSet() {
          return FeatureSet.latest();
        }
      };
    }
docs: Create a no-op pass that can only run once. Used to break up loops.