code: public Proxy setFtpProxy(String ftpProxy) {
      verifyProxyTypeCompatibility(ProxyType.MANUAL);
      this.proxyType = ProxyType.MANUAL;
      this.ftpProxy = ftpProxy;
      return this;
    }
docs: Specify which proxy to use for FTP connections.
  
  @param ftpProxy the proxy host, expected format is <code>hostname.com:1234</code>
  @return reference to self