code: public AsyncFuture getFutureFromIndex(int theIndex) {
          if (theIndex == READ_FUTURE_INDEX || theIndex == SYNC_READ_FUTURE_INDEX) {
              return this.readFuture;
          }
          if (theIndex == WRITE_FUTURE_INDEX || theIndex == SYNC_WRITE_FUTURE_INDEX) {
              return this.writeFuture;
          }
          return null;
      }
docs: Gets the Future corresponding to a supplied index value.
  
  @param theIndex the index value of the Future
  @return the Future corresponding to the index number. null if there is no Future which
  corresponds to the supplied Index