val creator = cache.edit("k1")!!
    creator.setString(0, "ABC")
    creator.setString(1, "DE")
    assertThat(creator.newSource(0)).isNull()
    assertThat(creator.newSource(1)).isNull()
    creator.commit()
    val snapshot = cache["k1"]!!
    snapshot.assertValue(0, "ABC")
    snapshot.assertValue(1, "DE")
  }

  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)