code: protected boolean isWebSocketsUpgradeRequest(HttpRequest request) {
          String connectionHeader = request.getHeader( Names.CONNECTION );
          String upgradeHeader = request.getHeader( Names.UPGRADE );
  
          if (connectionHeader == null || upgradeHeader == null) {
              return false;
          }
  
          if (connectionHeader.trim().toLowerCase().contains( Values.UPGRADE.toLowerCase() )) {
              if (upgradeHeader.trim().equalsIgnoreCase( Values.WEBSOCKET )) {
                  return true;
              }
          }
  
          return false;
      }
docs: Determine if this request represents a web-socket upgrade request.
  
  @param request The request to inspect.
  @return <code>true</code> if this request is indeed a web-socket upgrade
  request, otherwise <code>false</code>.