code: public static <A> Will<A> forListenableFuture(ListenableFuture<A> future) {
          return new Of<A>(future);
      }
docs: Creates Will object from Guava's {@link com.google.common.util.concurrent.ListenableFuture}
  
  @param future Guava's ListenableFuture
  @param <A>    Type of ListenableFuture and will be created
  @return Created Will