code: def ifetch_single(iterable, key, default=EMPTY, getter=None):
      
  
      def _getter(item):
          if getter:
              custom_getter = partial(getter, key=key)
              return custom_getter(item)
          else:
              return partial(bget, key=key, default=default)(item)
  
      return map(_getter, iterable)
docs: getter() g(item, key):pass