docs: public Decision addDecision(SoftwareSystem softwareSystem, String id, Date date, String title, DecisionStatus status, Format format, String content) {
          checkIdIsSpecified(id);
          checkTitleIsSpecified(title);
          checkContentIsSpecified(content);
          checkDecisionStatusIsSpecified(status);
          checkFormatIsSpecified(format);
          checkDecisionIsUnique(softwareSystem, id);
  
          Decision decision = new Decision(softwareSystem, id, date, title, status, format, content);
          this.decisions.add(decision);
  
          return decision;
      }