@Test
public void testSplitByFileId_twoFiles_primary() {

    final List<SamplingPoint> points = new ArrayList<>();
    points.add(createSamplingPointWithReference(22));
    points.add(createSamplingPointWithReference(19));
    points.add(createSamplingPointWithReference(22));
    points.add(createSamplingPointWithReference(22));
    points.add(createSamplingPointWithReference(19));
    final Map<Integer, List<SamplingPoint>> listByFileId = DirtySubsceneRemover.splitByFileId(points, true);
    assertEquals(2, listByFileId.size());
     List<SamplingPoint> fileList = listByFileId.get(19);
    assertNotNull(fileList);
    assertEquals(2, fileList.size());
    fileList = listByFileId.get(22);
    assertNotNull(fileList);
    assertEquals(3, fileList.size());
}