public void test_tryStartOperation_singleArg_delegatesToTwoArg() {
        // tryStartOperation(name) should delegate to tryStartOperation(name, null)
        final AtomicReference<String> passedData = new AtomicReference<>("NOT_NULL");
        final CoordinatorHelper helper = new CoordinatorHelper() {
            @Override
            public boolean tryStartOperation(final String operationName, final String data) {
                passedData.set(data);

     *
     * @param operationName the operation name used as the lock document ID.
     * @return {@code true} if the lock was acquired.
     */
    public boolean tryStartOperation(final String operationName) {
        return tryStartOperation(operationName, null);
    }

    /**
     * Attempts to acquire a distributed lock for the specified operation with optional data.
     *

        validate(form, messages -> {}, this::asIndexHtml);
        verifyToken(this::asIndexHtml);
        final CoordinatorHelper coordinator = ComponentUtil.getCoordinatorHelper();
        if (!coordinator.tryStartOperation("reload_doc_index")) {
            saveError(messages -> messages.addErrorsOperationAlreadyRunning(GLOBAL,
                    coordinator.getOperationInfo("reload_doc_index").map(o -> o.hostname).orElse("unknown")));