@Test
  public void testDeleteAsyncStringValue() throws Exception {
    String key = "key";
    Bucket bucket = mock(Bucket.class);
    AsyncBucket asyncBucket = mock(AsyncBucket.class);
    CouchbaseTableWriteFunction<String> writeFunction =
        createAndInit(String.class, new StringSerde(), bucket, asyncBucket);
    when(asyncBucket.remove(eq(key), anyLong(), any(TimeUnit.class))).thenReturn(Observable.just(null));
    assertNull(writeFunction.deleteAsync(key).get());
  }
This class performs unit tests for CouchbaseTableWriteFunction.
samza-kv-couchbase/src/test/java/org/apache/samza/table/remote/couchbase/TestCouchbaseTableWriteFunction.java