code: def next_counter(start=0, step=1):
      r
      count_gen = it.count(start, step)
      next_ = functools.partial(six.next, count_gen)
      return next_
docs: r"""
      Args:
          start (int): (default = 0)
          step (int): (default = 1)
  
      Returns:
          func: next_
  
      CommandLine:
          python -m utool.util_iter --test-next_counter
  
      Example:
          >>> # ENABLE_DOCTEST
          >>> from utool.util_iter import *  # NOQA
          >>> start = 1
          >>> step = 1
          >>> next_ = next_counter(start, step)
          >>> result = str([next_(), next_(), next_()])
          >>> print(result)
          [1, 2, 3]