code: def move(self, item, new_position):
          
          if item == self[new_position]:
              return
  
          self.remove(item)
          self.insert(new_position, item)
docs: Moves a item list to new position
  
          Calls observer ``self.observer(UpdateType.DELETED, item, index)``
          and observer ``self.observer(UpdateType.CREATED, item, index)``
          if ``val != self[index]``
  
          :param item: Item that will be moved to new_position
          :param new_position: Item's new position