code: def remove_bucket_list_item(self, id, collection, item):
          
          if type(id) is not ObjectId:
              id = ObjectId(id)
          obj = getattr(self.db, collection)
          result = obj.update(
              {'_id': id},
              {'$pull': {'bucket_list': item}}
          )
          return result
docs: Removes an item from the bucket list
  
          Args:
              id: the CRITs object id of the TLO
              collection: The db collection. See main class documentation.
              item: the bucket list item to remove
          Returns:
              The mongodb result