code: public static void hijackJDKLogging() {
          JUL_HIJACKING_LOCK.lock();
          try {
              if (!julHijacked) {
                  SLF4JBridgeHandler.removeHandlersForRootLogger();
                  SLF4JBridgeHandler.install();
                  julHijacked = true;
              }
          } finally {
              JUL_HIJACKING_LOCK.unlock();
          }
      }
docs: Gets the root j.u.l.Logger and removes all registered handlers
  then redirects all active j.u.l. to SLF4J
  <p/>
  N.B. This should only happen once, hence the flag and locking