def METHOD_NAME(self):
    res = _xy_range(np.array([[1, 2], [2, 2], [3, 3], [4, 2]]))
    self.assertTupleEqual((1, 4, 2, 3), res)
    # examples collinear along x axis
    res = _xy_range(np.array([[1, 2], [2, 2], [3, 2]]))
    self.assertTupleEqual((1, 3, 1.5, 2.5), res)
    # examples collinear along y axis
    res = _xy_range(np.array([[2, 1], [2, 2], [2, 3]]))
    self.assertTupleEqual((1.5, 2.5, 1, 3), res)
    # one point
    res = _xy_range(np.array([[2, 1]]))
    self.assertTupleEqual((1.5, 2.5, 0.5, 1.5), res)