### Question:
RemoteInputChannel extends InputChannel implements BufferRecycler, BufferListener { public void onFailedPartitionRequest() { inputGate.triggerPartitionStateCheck(partitionId); } RemoteInputChannel(
		SingleInputGate inputGate,
		int channelIndex,
		ResultPartitionID partitionId,
		ConnectionID connectionId,
		ConnectionManager connectionManager,
		TaskIOMetricGroup metrics);  RemoteInputChannel(
		SingleInputGate inputGate,
		int channelIndex,
		ResultPartitionID partitionId,
		ConnectionID connectionId,
		ConnectionManager connectionManager,
		int initialBackOff,
		int maxBackoff,
		TaskIOMetricGroup metrics); @VisibleForTesting @Override void requestSubpartition(int subpartitionIndex); @Override boolean isReleased(); @Override String toString(); @Override void recycle(MemorySegment segment); int getNumberOfAvailableBuffers(); int getNumberOfRequiredBuffers(); int getSenderBacklog(); @Override NotificationResult notifyBufferAvailable(Buffer buffer); @Override void notifyBufferDestroyed(); int getUnannouncedCredit(); int getAndResetUnannouncedCredit(); int getNumberOfQueuedBuffers(); int unsynchronizedGetNumberOfQueuedBuffers(); InputChannelID getInputChannelId(); int getInitialCredit(); BufferProvider getBufferProvider(); @Nullable Buffer requestBuffer(); void onBuffer(Buffer buffer, int sequenceNumber, int backlog); void onEmptyBuffer(int sequenceNumber, int backlog); void onFailedPartitionRequest(); void onError(Throwable cause);  }### Answer:
@Test public void testOnFailedPartitionRequest() throws Exception { final ConnectionManager connectionManager = mock(ConnectionManager.class); when(connectionManager.createPartitionRequestClient(any(ConnectionID.class))) .thenReturn(mock(PartitionRequestClient.class)); final ResultPartitionID partitionId = new ResultPartitionID(); final SingleInputGate inputGate = mock(SingleInputGate.class); final RemoteInputChannel ch = new RemoteInputChannel( inputGate, 0, partitionId, mock(ConnectionID.class), connectionManager, UnregisteredMetricGroups.createUnregisteredTaskMetricGroup().getIOMetricGroup()); ch.onFailedPartitionRequest(); verify(inputGate).triggerPartitionStateCheck(eq(partitionId)); }