code: protected void populateResponseHeaders(Set<String> requestHeaderKeys, Map<String,String> metaInfo, HttpServletResponse response) {
          for (String key : metaInfo.keySet()) {
              if (!Listener.AUTHENTICATED_USER_HEADER.equals(key)
                      && !Listener.AUTHENTICATED_JWT.equals(key)
                      && !Listener.METAINFO_HTTP_STATUS_CODE.equals(key)
                      && !Listener.METAINFO_ACCEPT.equals(key)
                      && !Listener.METAINFO_CONTENT_TYPE.equals(key)
                      && !Listener.METAINFO_DOWNLOAD_FORMAT.equals(key)
                      && !Listener.METAINFO_MDW_REQUEST_ID.equals(key)
                      && !requestHeaderKeys.contains(key))
                  response.setHeader(key, metaInfo.get(key));
          }
  
          // these always get populated if present
          if (metaInfo.get(Listener.METAINFO_REQUEST_ID) != null)
              response.setHeader(Listener.METAINFO_REQUEST_ID, metaInfo.get(Listener.METAINFO_REQUEST_ID));
          if (metaInfo.get(Listener.METAINFO_MDW_REQUEST_ID) != null && !metaInfo.get(Listener.METAINFO_MDW_REQUEST_ID).equals("0"))
              response.setHeader(Listener.METAINFO_MDW_REQUEST_ID, metaInfo.get(Listener.METAINFO_MDW_REQUEST_ID));
          if (metaInfo.get(Listener.METAINFO_CORRELATION_ID) != null)
              response.setHeader(Listener.METAINFO_CORRELATION_ID, metaInfo.get(Listener.METAINFO_CORRELATION_ID));
          if (metaInfo.get(Listener.METAINFO_DOCUMENT_ID) != null)
              response.setHeader(Listener.METAINFO_DOCUMENT_ID, metaInfo.get(Listener.METAINFO_DOCUMENT_ID));
      }
docs: Populates response headers with values added by event handling.