code: public void setProxy(Proxy proxy) {
          if (config.delivery instanceof HttpDelivery) {
              ((HttpDelivery) config.delivery).setProxy(proxy);
          }
          if (config.sessionDelivery instanceof HttpDelivery) {
              ((HttpDelivery) config.sessionDelivery).setProxy(proxy);
          }
      }
docs: Set a proxy to use when delivering Bugsnag error reports and sessions. This is a convenient
  shorthand for bugsnag.getDelivery().setProxy();
  
  @param proxy the proxy to use to send reports