code: public Collection<SecondaryWorkitem> getSecondaryWorkitems(SecondaryWorkitemFilter filter,
                                                                 boolean includeSubprojects) {
          filter = (filter != null) ? filter : new SecondaryWorkitemFilter();
  
          return getInstance().get().secondaryWorkitems(
                  getFilter(filter, includeSubprojects));
      }
docs: Get SecondaryWorkitems in this Project filtered as specified in the
  passed in filter.
  
  @param filter             Criteria to filter on. Project will be set automatically.
  If null, all tasks and tests in the project are returned.
  @param includeSubprojects Specifies whether to include items from sub
  project or not. This only adds open subprojects.
  @return An Collection of SecondaryWorkitem.