### Question:
FlushStrategies { public static FlushStrategy flushOnEach() { return FLUSH_ON_EACH; } private  FlushStrategies(); static FlushStrategy defaultFlushStrategy(); static FlushStrategy flushOnEach(); static FlushStrategy batchFlush(int batchSize, Publisher<?> durationBoundaries); static FlushStrategy flushWith(Publisher<?> flushBoundaries); static FlushStrategy flushOnEnd();  }### Answer:
@Test public void testFlushOnEach() { setupFor(flushOnEach()); listener.itemWritten(1); listener.itemWritten(2); verifyFlush(2); }
@Test public void testSourceEmitErrorForFlushOnEach() { setupFor(flushOnEach()); listener.writeTerminated(); }