if (proxyHost != null) {
configBuilder.setProxyServer(new ProxyServer(proxyProtocol, proxyHost, proxyPort, proxyPrincipal, proxyPassword));
}
configBuilder.addIOExceptionFilter(new ResumableIOExceptionFilter());
SimpleAsyncHttpClient sc = new SimpleAsyncHttpClient(configBuilder.build(), requestBuilder, defaultThrowableHandler, errorDocumentBehaviour, enableResumableDownload, ahc, listener);
return sc;
}