code: def _build_instance_group_list_args(self, instance_groups):
          
          if type(instance_groups) != types.ListType:
              instance_groups = [instance_groups]
  
          params = {}
          for i, instance_group in enumerate(instance_groups):
              ig_dict = self._build_instance_group_args(instance_group)
              for key, value in ig_dict.iteritems():
                  params['InstanceGroups.member.%d.%s' % (i+1, key)] = value
          return params
docs: Takes a list of InstanceGroups, or a single InstanceGroup. Returns
          a comparable dict for use in making a RunJobFlow or AddInstanceGroups
          request.