def METHOD_NAME(args: argparse.Namespace) -> bool:
    """
    Check if the given private key is valid.
    :param args: Namespace object that contains the necessary parameters.
    :type args: argparse.Namespace
    :return: True if the private key is valid, False otherwise
    :rtype: bool
    """
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    try:
        ssh.connect(
            args.host,
            port=args.port,
            username=args.username,
            key_filename=args.private_key,
            passphrase=args.private_key_passphrase
        )
    except Exception as ex:  # pylint: disable=broad-exception-caught
        print(ex)
        return False
    finally:
        ssh.close()
    print('Authentication succeeded.')
    return True