try (ServletOutputStream out = response.getOutputStream(); InputStream in = curlResponse.getContentAsStream()) {
                response.setStatus(curlResponse.getHttpStatusCode());
                writeHeaders(response);
                final String responseContentType = curlResponse.getHeaderValue("Content-Type");
                if (StringUtil.isBlank(responseContentType)) {

            if (!used.contains(vq)) {
                groupedQueries.add(vq);
            }
        }
        return groupedQueries.toArray(new String[0]);
    }

    @Override
    protected void writeHeaders(final HttpServletResponse response) {
        ComponentUtil.getFessConfig().getApiJsonResponseHeaderList().forEach(e -> response.setHeader(e.getFirst(), e.getSecond()));
    }

        }

        @Override
        public HighlightInfo getHighlightInfo() {
            return new HighlightInfo();
        }
    }

    @Override
    protected void writeHeaders(final HttpServletResponse response) {
        ComponentUtil.getFessConfig().getApiJsonResponseHeaderList().forEach(e -> response.setHeader(e.getFirst(), e.getSecond()));
    }

    /**