code: public static void configureCustomProxyProperties(
        Map<SFSessionProperty, Object> connectionPropertiesMap)
    {
      if (connectionPropertiesMap.containsKey(SFSessionProperty.USE_PROXY))
      {
        useProxy = (boolean) connectionPropertiesMap.get(
            SFSessionProperty.USE_PROXY);
      }
  
      if (useProxy)
      {
        proxyHost =
            (String) connectionPropertiesMap.get(SFSessionProperty.PROXY_HOST);
        proxyPort =
            Integer.parseInt(
                connectionPropertiesMap.get(SFSessionProperty.PROXY_PORT).toString());
        proxyUser =
            (String) connectionPropertiesMap.get(SFSessionProperty.PROXY_USER);
        proxyPassword =
            (String) connectionPropertiesMap.get(SFSessionProperty.PROXY_PASSWORD);
        nonProxyHosts =
            (String) connectionPropertiesMap.get(SFSessionProperty.NON_PROXY_HOSTS);
      }
    }
docs: configure custom proxy properties from connectionPropertiesMap