public static HttpURLConnection openPostConnection(final URL url, final Map<String, String> headers) throws IOException {
        return openConnection(url, HttpConstants.HTTP_METHOD.POST.name(), headers);
    }
<p>openPostConnection.</p>

@param url a {@link URL} object
@param headers a {@link Map} object
@return a {@link HttpURLConnection} object
@throws IOException if any.
pac4j-core/src/main/java/org/pac4j/core/util/HttpUtils.java