private boolean allChunksWritten() {
      return responseCompleteCalled.get() && !writeFuture.isDone() && chunksToWriteCount.get() == 0;
    }
Determines if input has ended by examining response state and number of chunks pending for write.
@return {@code true} if there are no more chunks to write. {@code false} otherwise.
ambry-rest/src/main/java/com/github/ambry/rest/NettyResponseChannel.java