docs: public WriteCampaignRequest withAdditionalTreatments(WriteTreatmentResource... additionalTreatments) {
          if (this.additionalTreatments == null) {
              setAdditionalTreatments(new java.util.ArrayList<WriteTreatmentResource>(additionalTreatments.length));
          }
          for (WriteTreatmentResource ele : additionalTreatments) {
              this.additionalTreatments.add(ele);
          }
          return this;
      }