code: def get(cls, ns, key):
          
          return getattr(db, cls.__name__).find_one(
              ConfigItem.namespace_prefix == ns,
              ConfigItem.key == key
          )
docs: Fetch an item by namespace and key
  
          Args:
              ns (str): Namespace prefix
              key (str): Item key
  
          Returns:
              :obj:`Configitem`: Returns config item object if found, else `None`