code: public Filter createFilter(FilterFactoryParams params) throws FilterNotCreatedException {
          try {
              return createFilter(parseCategories(params.getArgs()));
          } catch (ClassNotFoundException e) {
              throw new FilterNotCreatedException(e);
          }
      }
docs: Creates a {@link org.junit.experimental.categories.Categories.CategoryFilter} given a
  {@link FilterFactoryParams} argument.
  
  @param params Parameters needed to create the {@link Filter}