@Override
      public void complete() {
        if (pendingChunks.decrementAndGet() <= 0) {
          latch.countDown();
          rv.signalComplete();
        }
      }
Asynchronously get a bunch of objects from the cache.

@param <T>
@param keyIter Iterator that produces keys.
@param tcIter an iterator of transcoders to serialize and unserialize
         values; the transcoders are matched with the keys in the same
         order. The minimum of the key collection length and number of
         transcoders is used and no exception is thrown if they do not
         match
@return a Future result of that fetch
@throws IllegalStateException in the rare circumstance where queue is too
          full to accept any more requests
src/main/java/net/spy/memcached/MemcachedClient.java