waiter1.start();
    waiter1.awaitWaiting();

    WaiterThread waiter2 = new WaiterThread(future);
    waiter2.start();
    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

    waiter1.start();
    waiter1.awaitWaiting();

    WaiterThread waiter2 = new WaiterThread(future);
    waiter2.start();
    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

		return nil, err
	}

	// Establish file header and initial data area if not already present.
	if info.Size() < minFileLen {
		if _, err := f.WriteAt(hdr, 0); err != nil {
			return nil, err
		}
		// Write zeros at the end of the file to extend it to minFileLen.
		if _, err := f.WriteAt(m.zero[:], int64(minFileLen-len(m.zero))); err != nil {
			return nil, err
		}
		info, err = f.Stat()
		if err != nil {
			return nil, err

        val outputStream = ByteArrayOutputStream()
        writeTo(
            outputStream, graph, codec,
            object : AbstractProblemsListener() {
                override fun onProblem(problem: PropertyProblem) {
                    println(problem)
                }
            }
        )
        return outputStream.toByteArray()
    }

    private
    fun writeTo(
        outputStream: OutputStream,

					defer grid.PutByteBuffer(buf)

					writers[i] = newStreamingBitrotWriterBuffer(inlineBuffers[i], DefaultBitrotAlgorithm, erasure.ShardSize())
				} else {
					writers[i] = newBitrotWriter(disk, bucket, minioMetaTmpBucket, partPath,
						tillOffset, DefaultBitrotAlgorithm, erasure.ShardSize())
				}
			}

			// Heal each part. erasure.Heal() will write the healed

	}

	if len(buffer) > int(fi.Erasure.BlockSize) {
		buffer = buffer[:fi.Erasure.BlockSize]
	}
	writers := make([]io.Writer, len(onlineDisks))
	for i, disk := range onlineDisks {
		if disk == nil {
			continue
		}
		writers[i] = newBitrotWriter(disk, bucket, minioMetaTmpBucket, tmpPartPath, erasure.ShardFileSize(data.Size()), DefaultBitrotAlgorithm, erasure.ShardSize())
	}

					slowCh <- obj
					continue
				}

				batch = append(batch, obj.Item)

				if len(batch) < *r.Source.Snowball.Batch {
					continue
				}
				writeFn(batch)
				batch = batch[:0]
			}
			writeFn(batch)
			xioutil.SafeClose(slowCh)
		}()
	} else {
		slowCh = walkCh
	}

		c.blockMessages.Store(&block)
		c.connMu.Unlock()
	}
}

// wsWriter writes websocket messages.
type wsWriter struct {
	tmp [ws.MaxHeaderSize]byte
}

// writeMessage writes a message to w without allocations.
func (ww *wsWriter) writeMessage(w io.Writer, s ws.State, op ws.OpCode, p []byte) error {
	const fin = true
	var frame ws.Frame
	if s.ClientSide() {

	if cap(buf) < len(buf)+20 {
		b := make([]byte, len(buf), 20+cap(buf)*2)
		copy(b, buf)
		buf = b
	}
	writeAt := len(buf)
	buf = buf[0 : len(buf)+ctxt.Arch.PtrSize]
	writePtr(ctxt, buf[writeAt:], word)
	return buf
}

// Write a pointer-sized uint to the beginning of buf.
func writePtr(ctxt *obj.Link, buf []byte, word uint64) {
	switch ctxt.Arch.PtrSize {
	case 4:

// writeBlocks writes a specified chunk of symbols to the output buffer. It
// breaks the write up into ≥blockSize chunks to write them out, and schedules
// as many goroutines as necessary to accomplish this task. This call then
// blocks, waiting on the writes to complete. Note that we use the sem parameter
// to limit the number of concurrent writes taking place.