public static boolean isPathPresent(MaskTree filter, PathSpec path)
  {
    return !getPresentPaths(filter, Collections.singleton(path)).isEmpty();
  }
@Test
  public void testEmptyPath()
  {
    final MaskTree filter = new MaskTree();
    filter.addOperation(new PathSpec("foo"), MaskOperation.POSITIVE_MASK_OP);

    Assert.assertTrue(ProjectionUtil.isPathPresent(filter, new PathSpec()));
  }