code: func (el *eventLogger) EventBegin(ctx context.Context, event string, metadata ...Loggable) *EventInProgress {
  	ctx = el.Start(ctx, event)
  
  	for _, m := range metadata {
  		for l, v := range m.Loggable() {
  			el.LogKV(ctx, l, v)
  		}
  	}
  
  	eip := &EventInProgress{}
  	eip.doneFunc = func(additional []Loggable) {
  		// anything added during the operation
  		// e.g. deprecated methods event.Append(...) or event.SetError(...)
  		for _, m := range eip.loggables {
  			for l, v := range m.Loggable() {
  				el.LogKV(ctx, l, v)
  			}
  		}
  		el.Finish(ctx)
  	}
  	return eip
  }
docs: // DEPRECATED use `Start`