code: @Override
      public String getGroupSummaryForWorkUnit( final DocWorkUnit workUnit){
          String groupSummary = workUnit.getDocumentedFeature().groupSummary();
          final CommandLineProgramGroup clpGroup = workUnit.getCommandLineProgramGroup();
          if (groupSummary == null || groupSummary.isEmpty()) {
              if (clpGroup != null) {
                  groupSummary = clpGroup.getDescription();
              }
              if (groupSummary == null || groupSummary.isEmpty()) {
                  logger.warn("No group summary declared for: " + workUnit.getClazz().getCanonicalName());
                  groupSummary = "";
              }
          }
          return groupSummary;
      }
docs: Get the group summary string to be used for a given work unit's group, applying any fallback policy.
  This is called by the work unit handler after the work unit has been populated, and may be overridden by
  subclasses to provide custom behavior.
  
  @param workUnit
  @return the group summary to be used for this work unit's group