def test_invert_y_two(self):
"""Test a more complicated Y axis inversion."""
z = 13
y = 31
assert Mercator.invert_y(z, y) == 8160
def test_invert_y_one(self):
"""Test inverted Y axis calculation."""
z = 1
y = 0
assert Mercator.invert_y(z, y) == 1