assertTrue(sink.totalBuffered > 0);
long amountInChunk = sink.totalBuffered;
// Get a chunk
RegionEntryBuffer chunk = sink.getChunkToWrite();
assertEquals(chunk.heapSize(), amountInChunk);
// Make sure it got marked that a thread is "working on this"
assertTrue(sink.isRegionCurrentlyWriting(TEST_REGION));
// Insert some more entries