def METHOD_NAME():
    m = UnitSquareMesh(1, 1)
    mesh = ExtrudedMesh(m, layers=2)
    U = VectorFunctionSpace(mesh, 'DG', 0)
    u = TrialFunction(U)
    v = TestFunction(U)
    n = FacetNormal(mesh)
    temp = assemble(avg(inner(dot(u, n), dot(v, n)))*dS_h)
    assert temp.M.values[0, 0] == 0.0
    assert temp.M.values[1, 1] == 0.0
    assert temp.M.values[2, 2] != 0.0