/**
  * Configure type of proxy.
  *
  * @param proxyType Type of proxy as
  * @return the current {@link Builder} instance
  */
 public Builder proxyType(Proxy.Type proxyType) {
   if (proxy == null) {
     proxy = new ProxyConfig(Proxy.Type.HTTP);
   }
   proxy.setProxyType(proxyType);
   return this;
 }