def test_lazy_slice(self):
data = Data([1, 2, 3, 4])
assert list(data) == [1, 2, 3, 4]
assert data.index == range(0, 4)
assert list(data.lazy_slice([3, 2, 1])) == [4, 3, 2]
assert data.index == range(0, 4)
def test_lazy_slice_works_on_array(self):
data = Data([[1, 2, 3], [2, 3, 4]], index=[0, 1, 2])
assert list(data.lazy_slice([0])) == [[1, 2, 3]]
assert data[1] == [2, 3, 4]