def METHOD_NAME(self, User):
    """Should derive the correct column length from the specified schemes.
    """
    from passlib.hash import pbkdf2_sha512
    kind = inspect(User).c.password.type
    # name + rounds + salt + hash + ($ * 4) of largest hash
    expected_length = len(pbkdf2_sha512.name)
    expected_length += len(str(pbkdf2_sha512.max_rounds))
    expected_length += pbkdf2_sha512.max_salt_size
    expected_length += pbkdf2_sha512.encoded_checksum_size
    expected_length += 4
    assert kind.length == expected_length