docs: private HazelcastInstance getOrCreateByInstanceName(String instanceName) {
          HazelcastInstance instance = HazelcastClient.getHazelcastClientByName(instanceName);
          if (instance == null) {
              ClientConfig clientConfig = getDefaultClientConfig();
              clientConfig.setInstanceName(instanceName);
              instance = HazelcastClient.newHazelcastClient(clientConfig);
          }
          return instance;
      }