code: def match_version(desired, available, cmp_func=None, ignore_epoch=False):
      '''
      Returns the first version of the list of available versions which matches
      the desired version comparison expression, or None if no match is found.
      '''
      oper, version = split_comparison(desired)
      if not oper:
          oper = '=='
      for candidate in available:
          if salt.utils.versions.compare(ver1=candidate,
                                         oper=oper,
                                         ver2=version,
                                         cmp_func=cmp_func,
                                         ignore_epoch=ignore_epoch):
              return candidate
      return Nonf match_version(desired, available, cmp_func=None, ignore_epoch=False):
      '''
      Returns the first version of the list of available versions which matches
      the desired version comparison expression, or None if no match is found.
      '''
      oper, version = split_comparison(desired)
      if not oper:
          oper = '=='
      for candidate in available:
          if salt.utils.versions.compare(ver1=candidate,
                                         oper=oper,
                                         ver2=version,
                                         cmp_func=cmp_func,
                                         ignore_epoch=ignore_epoch):
              return candidate
      return None
docs: Returns the first version of the list of available versions which matches
      the desired version comparison expression, or None if no match is found.