code: public String getPromotionDetailsJsonModel() throws IOException {
          final PromotionEvaluationReport sampleReport = new PromotionEvaluationReport();
          sampleReport.addMessage(String.format(TWO_PLACES, PromotionReportTranslator.UNPROMOTED_MSG, "com.acme.secure-smh:core-relay:1.2.0"), MAJOR);
          sampleReport.addMessage(String.format(TWO_PLACES, PromotionReportTranslator.DO_NOT_USE_MSG, "com.google.guava:guava:20.0"), MAJOR);
          sampleReport.addMessage(String.format(TWO_PLACES, PromotionReportTranslator.MISSING_LICENSE_MSG, "org.apache.maven.wagon:wagon-webdav-jackrabbit:2.12"), MINOR);
          sampleReport.addMessage(String.format(TWO_PLACES, PromotionReportTranslator.UNACCEPTABLE_LICENSE_MSG,
                  "aopaliance:aopaliance:1.0 licensed as Attribution-ShareAlike 2.5 Generic, " +
                  "org.polyjdbc:polyjdbc0.7.1 licensed as Creative Commons Attribution-ShareAlike 3.0 Unported License"),
                  MINOR);
  
          sampleReport.addMessage(PromotionReportTranslator.SNAPSHOT_VERSION_MSG, Tag.CRITICAL);
          return JsonUtils.serialize(sampleReport);
      }
docs: Returns an empty Promotion details in Json
  
  @return String
  @throws IOException