code: public Double getTotalDetailEstimate(WorkitemFilter filter) {
          filter = (filter != null) ? filter : new WorkitemFilter();
  
          return getSum("OwnedWorkitems", filter, "DetailEstimate");
      }
docs: Return the total detail estimate for all workitems owned by this member
  optionally filtered.
  
  @param filter Criteria to filter workitems on.
  @return total detail estimate of selected Workitems.