private String getHost(Request httpRequest) {
        return EndPointUtils.getEndPoint(httpRequest.getUrl(), null);
    }
intercept com.ning.http.client.AsyncHttpClient.executeRequest(Request,
AsyncHandler<T>)

@author netspider
@author jaehong.kim
agent-module/plugins/ning-asynchttpclient/src/main/java/com/navercorp/pinpoint/plugin/ning/asynchttpclient/interceptor/ExecuteRequestInterceptor.java