{ list: List<TestProjectDuration> -> MultipleTestProjectBucket(list) },
        numberOfBuckets,
        MAX_TEST_PROJECTS_PER_BUCKET,
        { numEmptyBuckets -> (0 until numEmptyBuckets).map { EmptyTestProjectBucket(it) }.toList() },
        { tests1, tests2 -> tests1 != tests2 }
    )
}