}

        final Deferred<T> deferred = new Deferred<>();
        try {
            processRequest(client, deferred);
        } catch (final Exception e) {
            throw new SuggesterException(e);
        }
        return deferred.promise();
    }

    protected abstract void processRequest(Client client, Deferred<T> deferred);

    protected abstract String getValidationError();

    }

    public void setQueryFreqThreshold(final int queryFreqThreshold) {
        this.queryFreqThreshold = queryFreqThreshold;
    }

    @Override
    protected void processRequest(final Client client, final Deferred<PopularWordsResponse> deferred) {
        final SearchRequestBuilder builder = client.prepareSearch(index);
        builder.setSize(size);
        builder.setQuery(buildQuery());