code: def register_area(self, area_code, index, userdata):
          
          size = ctypes.sizeof(userdata)
          logger.info("registering area %s, index %s, size %s" % (area_code,
                                                                  index, size))
          size = ctypes.sizeof(userdata)
          return self.library.Srv_RegisterArea(self.pointer, area_code, index,
                                               ctypes.byref(userdata), size)
docs: Shares a memory area with the server. That memory block will be
          visible by the clients.