code: def get_storage_controller_by_instance(self, connection_type, instance):
          
          if not isinstance(connection_type, StorageBus):
              raise TypeError("connection_type can only be an instance of type StorageBus")
          if not isinstance(instance, baseinteger):
              raise TypeError("instance can only be an instance of type baseinteger")
          storage_controller = self._call("getStorageControllerByInstance",
                       in_p=[connection_type, instance])
          storage_controller = IStorageController(storage_controller)
          return storage_controller
docs: Returns a storage controller of a specific storage bus
          with the given instance number.
  
          in connection_type of type :class:`StorageBus`
  
          in instance of type int
  
          return storage_controller of type :class:`IStorageController`
  
          raises :class:`VBoxErrorObjectNotFound`
              A storage controller with given instance number doesn't exist.