code: public Double getTotalDone(WorkitemFilter filter, boolean includeChildProjects) {
          filter = (filter != null) ? filter : new WorkitemFilter();
  
          return getRollup("Workitems", "Actuals.Value", filter,
                           includeChildProjects);
      }
docs: Retrieves the total done for all workitems in this project optionally
  filtered.
  
  @param filter               Criteria to filter workitems on.
  @param includeChildProjects If true, include open sub projects, otherwise
  only include this project.
  @return total done for selected workitems.