code: def map_sections(fun, neurites, neurite_type=NeuriteType.all, iterator_type=Tree.ipreorder):
      '''Map `fun` to all the sections in a collection of neurites'''
      return map(fun, iter_sections(neurites,
                                    iterator_type=iterator_type,
                                    neurite_filter=is_type(neurite_type))f map_sections(fun, neurites, neurite_type=NeuriteType.all, iterator_type=Tree.ipreorder):
      '''Map `fun` to all the sections in a collection of neurites'''
      return map(fun, iter_sections(neurites,
                                    iterator_type=iterator_type,
                                    neurite_filter=is_type(neurite_type)))
docs: Map `fun` to all the sections in a collection of neurites