def validate_certificates_by_serial_numbers(serial_numbers):
    """
    Ensuring that the specified certificate(s) exist.
    :param serial_numbers:
    :return:
    """
    if serial_numbers:
        all_certs = []
        for serial_number in serial_numbers:
            certs = get_by_serial(serial_number)

            if not certs or len(certs) == 0:
                click.echo(f"[-] No certificate found with serial number: {serial_number}")
                sys.exit(1)
            all_certs.extend(certs)

        return all_certs

    Ensuring that the specified certificate(s) exist.
    :param serial_numbers:
    :return:
    
lemur/certificates/cli.py