return null;
            }

            data.setContent(EntityUtils.toString(response.getEntity(), Charsets.UTF_8));
            final Header[] headers = response.getAllHeaders();
            for (final Header header : headers) {
                data.putValue(header.getName(), header.getValue());
            }
        } catch (final IOException e) {

                try {
                    final HttpResponse response = closeableHttpClient.execute(request, new BasicHttpContext(httpClientContext));
                    httpEntity = response.getEntity();
                    consumer.accept(response, httpEntity);
                } catch (final Exception e) {
                    request.abort();
                    logger.warn("Failed to authenticate on " + scheme, e);

                if (StringUtil.isNotBlank(tokenReqParams)) {
                    final HttpEntity httpEntity = parseRequestParameters(tokenReqParams, null, encoding);
                    httpPost.setEntity(httpEntity);
                }
                httpRequest = httpPost;
            } else {
                final StringBuilder buf = new StringBuilder(100);
                buf.append(tokenUrl);