class_docstr: Implement a ketama compatible consistent hashing ring.
docstr: Python 2 compatible int iterator from str.
  
  :param data: the string to int iterate upon.
code: def _listbytes(data):
      """Python 2 compatible int iterator from str.
  
      :param data: the string to int iterate upon.
      """
      return map(ord, data)
  
file_path: mars/mars/lib/uhashring/ring_ketama.py
imports: from bisect import insort
  from collections import Counter
  from hashlib import md5
  from sys import version_info
label_desc: Use image node_id 4 for calling the KetamaRing obj's underlying member method code with example usage: obj._listbytes(data) and returns: map