pager.go
func (p *Pager) Trigger(description string) (incidentKey string, err error) {
	return p.trigger(description, "", map[string]interface{}{})
}
func (p *Pager) Trigger(description string) (incidentKey string, err error) {
	return p.trigger(description, "", map[string]interface{}{})
}
// Trigger creates a new PagerDuty incident with the given description. The
// returned incident key can be used to resolve the incident. It can also be
// used by the "TriggerIncidentKey*" functions to trigger an incident only if
// that specific incident has been resolved.