def METHOD_NAME(W):
    u = TrialFunction(W)
    v = TestFunction(W)
    A = assemble(inner(u, v)*dx)
    assert A.M.sparsity.shape == (2, 2)
    # DGxDG block
    assert not np.allclose(A.M[0, 0].values, 0.0)
    # DGxRT block
    assert np.allclose(A.M[1, 0].values, 0.0)
    # RTxDG block
    assert np.allclose(A.M[0, 1].values, 0.0)
    # RTxRT block
    assert not np.allclose(A.M[1, 1].values, 0.0)