code: public Double getTotalToDo(WorkitemFilter filter, boolean includeChildProjects) {
          filter = (filter != null) ? filter : new WorkitemFilter();
  
          return getRollup("Workitems", "ToDo", filter, includeChildProjects);
      }
docs: Retrieves the total to do 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 to do of selected Workitems.