code: public static <T1, T2, T3> TriConsumer<T1, T2, T3> spy3rd(TriConsumer<T1, T2, T3> consumer, Box<T3> param3) {
          return spy(consumer, Box.<T1>empty(), Box.<T2>empty(), param3);
      }
docs: Proxies a ternary consumer spying for third parameter.
  
  @param <T1> the consumer first parameter type
  @param <T2> the consumer second parameter type
  @param <T3> the consumer third parameter type
  @param consumer the consumer that will be spied
  @param param3 a box that will be containing the third spied parameter
  @return the proxied consumer