code: func (l *Log) SearchSessionEvents(fromUTC time.Time, toUTC time.Time, limit int) ([]events.EventFields, error) {
  	// only search for specific event types
  	query := url.Values{}
  	query[events.EventType] = []string{
  		events.SessionStartEvent,
  		events.SessionEndEvent,
  	}
  	return l.SearchEvents(fromUTC, toUTC, query.Encode(), limit)
  }
docs: // SearchSessionEvents returns session related events only. This is used to
  // find completed session.