docs: public static void shutdown(String instanceName) {
          HazelcastClientProxy proxy = CLIENTS.remove(instanceName);
          if (proxy == null) {
              return;
          }
          HazelcastClientInstanceImpl client = proxy.client;
          if (client == null) {
              return;
          }
          proxy.client = null;
          try {
              client.shutdown();
          } catch (Throwable ignored) {
              EmptyStatement.ignore(ignored);
          } finally {
              OutOfMemoryErrorDispatcher.deregisterClient(client);
          }
      }