code: public static String getProxyHost(AppleServer server) {
  		String host = server != null ? server.getProxyHost() : null;
  		if (host != null && host.length() > 0) {
  			return host;
  		} else {
  			host = System.getProperty(LOCAL_PROXY_HOST_PROPERTY);
  			if (host != null && host.length() > 0) {
  				return host;
  			} else {
  				host = System.getProperty(JVM_PROXY_HOST_PROPERTY);
  				if (host != null && host.length() > 0) {
  					return host;
  				} else {
  					return null;
  				}
  			}
  		}
  	}
docs: Get the proxy host address currently configured.
  This method checks if a server-specific proxy has been configured,
  then checks if a proxy has been configured for the entire library,
  and finally checks if a JVM-wide proxy setting is available for HTTPS.
  @param server a specific server to check for proxy settings (may be null)
  @return a proxy host, or null if none is configured