### Question:
PartitionedOutputBuffer implements OutputBuffer { @Override public void abort(OutputBufferId bufferId) { requireNonNull(bufferId, "bufferId is null"); partitions.get(bufferId.getId()).destroy(); checkFlushComplete(); } PartitionedOutputBuffer(
            String taskInstanceId,
            StateMachine<BufferState> state,
            OutputBuffers outputBuffers,
            DataSize maxBufferSize,
            Supplier<LocalMemoryContext> systemMemoryContextSupplier,
            Executor notificationExecutor); @Override void addStateChangeListener(StateChangeListener<BufferState> stateChangeListener); @Override boolean isFinished(); @Override double getUtilization(); @Override boolean isOverutilized(); @Override OutputBufferInfo getInfo(); @Override void setOutputBuffers(OutputBuffers newOutputBuffers); @Override ListenableFuture<?> isFull(); @Override void enqueue(List<SerializedPage> pages); @Override void enqueue(int partitionNumber, List<SerializedPage> pages); @Override ListenableFuture<BufferResult> get(OutputBufferId outputBufferId, long startingSequenceId, DataSize maxSize); @Override void acknowledge(OutputBufferId outputBufferId, long sequenceId); @Override void abort(OutputBufferId bufferId); @Override void setNoMorePages(); @Override void destroy(); @Override void fail(); @Override long getPeakMemoryUsage();  }### Answer:
@Test public void testAbort() { PartitionedOutputBuffer buffer = createPartitionedBuffer( createInitialEmptyOutputBuffers(PARTITIONED) .withBuffer(FIRST, 0) .withBuffer(SECOND, 1) .withNoMoreBufferIds(), sizeOfPages(10)); for (int i = 0; i < 5; i++) { addPage(buffer, createPage(i), 0); addPage(buffer, createPage(i), 1); } buffer.setNoMorePages(); assertBufferResultEquals(TYPES, getBufferResult(buffer, FIRST, 0, sizeOfPages(1), NO_WAIT), bufferResult(0, createPage(0))); buffer.abort(FIRST); assertQueueClosed(buffer, FIRST, 0); assertBufferResultEquals(TYPES, getBufferResult(buffer, FIRST, 1, sizeOfPages(1), NO_WAIT), emptyResults(TASK_INSTANCE_ID, 0, true)); assertBufferResultEquals(TYPES, getBufferResult(buffer, SECOND, 0, sizeOfPages(1), NO_WAIT), bufferResult(0, createPage(0))); buffer.abort(SECOND); assertQueueClosed(buffer, SECOND, 0); assertFinished(buffer); assertBufferResultEquals(TYPES, getBufferResult(buffer, SECOND, 1, sizeOfPages(1), NO_WAIT), emptyResults(TASK_INSTANCE_ID, 0, true)); }