def diagram_filter(orig_sparse_diag, extension_chord, extended_sparse_diag):
    diag = Diagram(extended_sparse_diag)
    diag.compress()
    if (contains_one_move(diag) or
        contains_three_move(diag)):
        return False # Skip this diagram
    return True # Use this diagram
 def test_compress(self):
     diag = Diagram([(2, 8), (4, 10), (6, 16), (12, 14)])
     compressed_diag = Diagram([(1, 4), (2, 5), (3, 8), (6, 7)])
     diag.compress()
     self.assertEqual(diag, compressed_diag)