def METHOD_NAME():
    """Tests if both substates of a bipartition will yield the same log
    negativity"""
    M = 200
    cov = random_cov(num_modes=M, pure=False, nonclassical=True)
    modes_A = 111
    # make a list that contains all modes but 111:
    modes_B = list(range(M))
    modes_B.pop(111)
    E_A = log_negativity(cov, modes_A=modes_A)
    E_B = log_negativity(cov, modes_A=modes_B)
    assert np.isclose(E_A, E_B)