code: def next(self):
      '''Iterator next. Build up count of returned elements during iteration.'''
  
      # if iteration has not begun, begin it.
      if not self._iterator:
        self.__iter__()
  
      next = self._iterator.next()
      if next is not StopIteration:
        self._returned_inc(next)
      return nexf next(self):
      '''Iterator next. Build up count of returned elements during iteration.'''
  
      # if iteration has not begun, begin it.
      if not self._iterator:
        self.__iter__()
  
      next = self._iterator.next()
      if next is not StopIteration:
        self._returned_inc(next)
      return next
docs: Iterator next. Build up count of returned elements during iteration.