def test_unit(array):
vector = Vector(array)
vector_unit = vector.unit()
assert math.isclose(vector_unit.norm(), 1)
assert (vector.norm() * vector_unit).is_close(array)
assert vector_unit.is_parallel(vector)
angle = vector.angle_between(vector_unit)
assert math.isclose(angle, 0, abs_tol=ATOL)
def test_add_subtract(arrays):
array_point, array_vector = arrays
point = Point(array_point)
vector = Vector(array_vector)
point_2 = point + array_vector
assert math.isclose(point.distance_point(point_2), vector.norm())
point_3 = point_2 - array_vector
assert point.is_close(point_3)
