Some XML-RPC servers support the de facto introspection methods
under the XML-RPC system. namespace.
Zend_XmlRpc_Client provides special support for servers with
these capabilities.
A Zend_XmlRpc_Client_ServerIntrospection instance may be
retrieved by calling the getIntrospector() method of
Zend_XmlRpcClient. It can then be used to perform introspection
operations on the server.