def METHOD_NAME(self):
    # Symmetric positive definite banded matrix `a`
    a = array([[4.0, 1.0, 0.0, 0.0],
               [1.0, 4.0, 0.5, 0.0],
               [0.0, 0.5, 4.0, 0.2],
               [0.0, 0.0, 0.2, 4.0]])
    # Banded storage form of `a`.
    ab = array([[4.0, 4.0, 4.0, 4.0],
                [1.0, 0.5, 0.2, -1.0]])
    c = cholesky_banded(ab, lower=True)
    lfac = zeros_like(a)
    lfac[list(range(4)), list(range(4))] = c[0]
    lfac[(1, 2, 3), (0, 1, 2)] = c[1, :3]
    assert_array_almost_equal(a, dot(lfac, lfac.T))
    b = array([0.0, 0.5, 4.2, 4.2])
    x = cho_solve_banded((c, True), b)
    assert_array_almost_equal(x, [0.0, 0.0, 1.0, 1.0])