code: def collection_updated_percolator(mapper, connection, target):
      
      delete_collection_percolator(target)
      if target.dbquery is not None:
          new_collection_percolator(target)
docs: Create percolator when collection is created.
  
      :param mapper: Not used. It keeps the function signature.
      :param connection: Not used. It keeps the function signature.
      :param target: Collection where the percolator should be updated.