def METHOD_NAME():
    """NULL (0) reports width 0."""
    # given,
    phrase = u'abc\x00def'
    expect_length_each = (1, 1, 1, 0, 1, 1, 1)
    expect_length_phrase = sum(expect_length_each)
    # exercise,
    length_each = tuple(map(wcwidth.wcwidth, phrase))
    length_phrase = wcwidth.wcswidth(phrase, len(phrase))
    # verify.
    assert length_each == expect_length_each
    assert length_phrase == expect_length_phrase