docs: public static void shutdownAll() {
          for (HazelcastClientProxy proxy : CLIENTS.values()) {
              HazelcastClientInstanceImpl client = proxy.client;
              if (client == null) {
                  continue;
              }
              proxy.client = null;
              try {
                  client.shutdown();
              } catch (Throwable ignored) {
                  EmptyStatement.ignore(ignored);
              }
          }
          OutOfMemoryErrorDispatcher.clearClients();
          CLIENTS.clear();
      }