return httpClient.execute(httpRequest, new BasicHttpContext(httpClientContext));
    }

    protected Date parseLastModified(final String value) {
        final SimpleDateFormat sdf = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z", Locale.ENGLISH);
        try {
            return sdf.parse(value);
        } catch (final ParseException e) {
            return null;
        }
    }