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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_subject_with_local_validation(jwt_bu64, cert_obj):
 """Validate the JWT and return the subject it contains. - The JWT is validated by checking that it was signed with a CN certificate. - The returned subject can be trusted for authz and authn operations. - Possible validation errors include: - A trusted (TLS/SSL) connection could not be made to the CN holding the signing certificate. - The JWT could not be decoded. - The JWT signature signature was invalid. - The JWT claim set contains invalid "Not Before" or "Expiration Time" claims. Args: jwt_bu64: bytes The JWT encoded using a a URL safe flavor of Base64. cert_obj: cryptography.Certificate Public certificate used for signing the JWT (typically the CN cert). Returns: - On successful validation, the subject contained in the JWT is returned. - If validation fails for any reason, errors are logged and None is returned. """

    try:
        jwt_dict = validate_and_decode(jwt_bu64, cert_obj)
    except JwtException as e:
        return log_jwt_bu64_info(logging.error, str(e), jwt_bu64)
    try:
        return jwt_dict['sub']
    except LookupError:
        log_jwt_dict_info(logging.error, 'Missing "sub" key', jwt_dict)