code: def update_attrs(self, old, new):
          
          #: Copy in storage from new node
          if new._d_storage:
              old._d_storage = new._d_storage
docs: Update any `attr` members.
  
              Parameters
              -----------
              old: Declarative
                  The existing view instance that needs to be updated
              new: Declarative
                  The new view instance that should be used for updating