code: public UnitMeta appendDescription(String descriptionToBeAppended) {
          if (getDescription() != null) {
              setDescription(getDescription().concat(descriptionToBeAppended));
          } else {
              setDescription(descriptionToBeAppended);
          }
          return this;
      }
docs: Append a description string to the end of current description
  
  @param descriptionToBeAppended description string you want to append
  @return this unit meta data