public String getUserAgent(Context ctx) {
   String userAgent = getPreferenceStringValue(SipConfigManager.USER_AGENT);
   if (userAgent.equalsIgnoreCase(CustomDistribution.getUserAgent())) {
     // If that's the official -not custom- user agent, send the release, the device and the api
     // level
     PackageInfo pinfo = getCurrentPackageInfos(ctx);
     if (pinfo != null) {
       userAgent +=
           "_"
               + android.os.Build.DEVICE
               + "-"
               + Compatibility.getApiLevel()
               + "/r"
               + pinfo.versionCode;
     }
   }
   return userAgent;
 }