code: @Override
    public UpdateRequestProcessor getInstance(SolrQueryRequest req,
        SolrQueryResponse rsp, UpdateRequestProcessor next) {
      try {
        init(req);
      } catch (IOException e) {
        log.error(e);
      }
      return new MtasUpdateRequestProcessor(next, config);
    }
docs: /*
  (non-Javadoc)
  
  @see
  org.apache.solr.update.processor.UpdateRequestProcessorFactory#getInstance(
  org.apache.solr.request.SolrQueryRequest,
  org.apache.solr.response.SolrQueryResponse,
  org.apache.solr.update.processor.UpdateRequestProcessor)