docs: def map(self, func):
          """ Return the results of applying the iterator to each element.
          """
          ns = self.Namespace()
          ns.results = []
  
          def by(value, index, list, *args):
              ns.results.append(func(value, index, list))
  
          _(self.obj).each(by)
          return self._wrap(ns.results)