@Test
  public void testDeleteNonExistentEntry() {
    this.inMemoryKeyValueStore.delete(key(0));

    assertNull(this.inMemoryKeyValueStore.get(key(0)));

    verify(this.deletesCounter, times(1)).inc();
  }
The length of the result of {@link #value(int)} will always be the same, so this can be used as the length for any
key produced by {@link #value(int)}.
samza-kv-inmemory/src/test/java/org/apache/samza/storage/kv/inmemory/TestInMemoryKeyValueStore.java