text: from server import infoServer
  class serverProxy:
      pass
  class infoServerProxy(serverProxy):
      server=""
      def __init__(self,server):
          self.server=server
      def recv(self,info):
          return self.server.recv(info)
      def show(self):
          self.server.show()
  
  class whiteInfoServerProxy(infoServerProxy):
      white_list=[]
      def recv(self,info):
          try:
              assert type(info)==dict
          except:
              return "info structure is not correct"
          addr=info.get("addr",0)
          if not addr in self.white_list:
              return "Your address is not in the white list."
          else:
              content=info.get("content","")
              return self.server.recv(content)
      def addWhite(self,addr):
          self.white_list.append(addr)
      def rmvWhite(self,addr):
          self.white_list.remove(addr)
      def clearWhite(self):
          self.white_list=[]
  
  
  if  __name__=="__main__":
      info_struct = dict()
      info_struct["addr"] = 10010
      info_struct["content"] = "Hello World!"
      info_server = infoServer()
      info_server_proxy = whiteInfoServerProxy(info_server)
      print (info_server_proxy.recv(info_struct))
      info_server_proxy.show()
      info_server_proxy.addWhite(10010)
      print (info_server_proxy.recv(info_struct))
      info_server_proxy.show()
  
  """
  output:
  Your address is not in the white list.
  SHOW:
  recv OK!
  SHOW:Hello World!
  """