code: public static <T> Predicate<T> spy1st(Predicate<T> predicate, Box<T> param) {
          return spy(predicate, Box.<Boolean>empty(), param);
      }
docs: Proxies a predicate spying for parameter.
  
  @param <T> the predicate parameter type
  @param predicate the predicate that will be spied
  @param param a box that will be containing spied parameter
  @return the proxied predicate