code: public ServletLimiterBuilder partitionByPathInfo(Function<String, String> pathToGroup) {
          return partitionResolver(request -> Optional.ofNullable(request.getPathInfo()).map(pathToGroup).orElse(null));
      }
docs: Partition the limit by the full path. Percentages of the limit are partitioned to named
  groups.  Group membership is derived from the provided mapping function.
  @param pathToGroup Mapping function from full path to a named group.
  @return Chainable builder