def create_finding(event: ExecutionBaseEvent, params: FindingFields):
    """
    Create a new notification message. This is the primary way that custom playbooks generate messages.
    """
    subject = event.get_subject()
    event.add_finding(
        Finding(
            title=format_event_templated_string(subject, params.title),
            description=format_event_templated_string(subject, params.description) if params.description else None,
            aggregation_key=params.aggregation_key,
            severity=FindingSeverity.from_severity(params.severity),
            subject=event.get_subject(),
            source=event.get_source(),
        )
    )

    Create a new notification message. This is the primary way that custom playbooks generate messages.
    
playbooks/robusta_playbooks/common_actions.py