code: public static <R> FuncN<R> fromFunc(final Func0<? extends R> f) {
          return new FuncN<R>() {
  
              @Override
              public R call(Object... args) {
                  if (args.length != 0) {
                      throw new RuntimeException("Func0 expecting 0 arguments.");
                  }
                  return f.call();
              }
  
          };
      }
docs: Converts a {@link Func0} to a {@link FuncN} to allow heterogeneous handling of functions with different arities.
  
  @param f the {@code Func0} to convert
  @return a {@link FuncN} representation of {@code f}