code: public void setSearchRoots(List<String> searchRoots) {
  
          if ((searchRoots != null) && !searchRoots.isEmpty()) {
              addFilterQuery(CmsSearchField.FIELD_PARENT_FOLDERS, searchRoots, false, true);
          }
      }
docs: Sets the search roots only if not set as query parameter.<p>
  
  @param searchRoots the searchRoots to set