### Question:
OperationConductor implements OnOperationCompleteListener { protected void drainPostProcessOperations() { LinkedList<OperationWrapper> recentCompletedOperations = new LinkedList<>(); postProcessingOperationQueue.drainTo(recentCompletedOperations); logger.info( "clearing the following complete operations: {}", recentCompletedOperations.stream().map(ow -> ow.getOperation().getName()).collect(Collectors.joining(", "))); recentCompletedOperations.forEach(this::postProcessCompletedOperation); } OperationConductor(Collection<Operation> operations, ExecutorContext executorContext,
        List<OperationConductorModifier> completedOperationModifiers);  OperationConductor(Collection<Operation> operations, ExecutorContext executorContext); void run(); @Override void onComplete(OperationWrapper operationWrapper); List<OperationWrapper> getRunningOperations(); List<OperationWrapper> getPendingOperations(); List<OperationWrapper> getFailedOperations(); JsonContextUpdater getJsonContextUpdater(); List<DiagnosticEvent> retrieveAllDiagnosticEvents(); boolean hasExecutionFailed(); String getFailedOperationsDelimited(String delimiter); void setCompletedOperationModifiers(List<OperationConductorModifier> completedOperationModifiers);  }### Answer:
@Test public void testDrainCompletedQueueEmpty() { operationConductor.drainPostProcessOperations(); }