code: public void shutDownNow() throws InterruptedException {
          synchronized (CassandraEmbeddedServer.SEMAPHORE) {
              LOGGER.info("Calling stop on Embedded Cassandra server");
              cassandraDaemonRef.get().stop();
  
              LOGGER.info("Calling shutdown on all Cluster instances");
              // First call shutdown on all registered Java driver Cluster instances
              orderedShutdownHook.callShutDown();
  
              LOGGER.info("Shutting down embedded Cassandra server");
              // Then shutdown the server
              executor.shutdownNow();
              CassandraEmbeddedServer.embeddedServerStarted = false;
          }
      }
docs: Trigger the shutdown of:
  <ul>
  <li><strong>the embedded Cassandra server</strong></li>
  <li><strong>the associated Cluster object</strong></li>
  <li><strong>the associated Session object</strong></li>
  </ul>