def METHOD_NAME(self):
    op = core.CreateOperator(
        'SparseToDenseMask',
        ['indices', 'values', 'default', 'lengths'],
        ['output'],
        mask=[999999999, 2, 888, 6])
    workspace.FeedBlob(
        'indices',
        np.array([2, 4, 6, 999999999, 2], dtype=np.int64))
    workspace.FeedBlob(
        'values',
        np.array([[[1, -1]], [[2, -2]], [[3, -3]], [[4, -4]], [[5, -5]]],
                 dtype=np.float))
    workspace.FeedBlob('default', np.array([[-1, 0]], dtype=np.float))
    workspace.FeedBlob('lengths', np.array([2, 3], dtype=np.int32))
    workspace.RunOperatorOnce(op)
    output = workspace.FetchBlob('output')
    expected = np.array([
        [[[-1, 0]], [[1, -1]], [[-1, 0]], [[-1, 0]]],
        [[[4, -4]], [[5, -5]], [[-1, 0]], [[3, -3]]]], dtype=np.float)
    self.assertEqual(output.shape, expected.shape)
    np.testing.assert_array_equal(output, expected)