### Question:
FileSingleStreamSpiller implements SingleStreamSpiller { @Override public ListenableFuture<?> spill(Iterator<Page> pageIterator) { requireNonNull(pageIterator, "pageIterator is null"); checkNoSpillInProgress(); spillInProgress = executor.submit(() -> writePages(pageIterator)); return spillInProgress; } FileSingleStreamSpiller(
            PagesSerde serde,
            ListeningExecutorService executor,
            Path spillPath,
            SpillerStats spillerStats,
            SpillContext spillContext,
            LocalMemoryContext memoryContext,
            Optional<SpillCipher> spillCipher,
            Runnable fileSystemErrorHandler); @Override ListenableFuture<?> spill(Iterator<Page> pageIterator); @Override long getSpilledPagesInMemorySize(); @Override Iterator<Page> getSpilledPages(); @Override ListenableFuture<List<Page>> getAllSpilledPages(); @Override void close();  }### Answer:
@Test public void testSpill() throws Exception { assertSpill(false, false); }