          An optional tuple/list of allowed suffixes.  eg ['json', 'api']
          Defaults to `None`, which allows any suffix.
  
      """
      suffix_kwarg = suffix_kwarg or api_settings.FORMAT_SUFFIX_KWARG
      if allowed:
          if len(allowed) == 1:
              allowed_pattern = allowed[0]
          else:
              allowed_pattern = '(%s)' % '|'.join(allowed)
 
</s> remove     suffix_kwarg:
        The name of the kwarg that will be passed to the view.
        Defaults to 'format'.

 </s> add  </s> remove def format_suffix_patterns(urlpatterns, suffix_required=False,
                           suffix_kwarg=None, allowed=None):
 </s> add def format_suffix_patterns(urlpatterns, suffix_required=False, allowed=None):
    suffix_kwarg = api_settings.FORMAT_SUFFIX_KWARG
          An optional tuple/list of allowed suffixes.  eg ['json', 'api']
          Defaults to `None`, which allows any suffix.
  
      """
    suffix_kwarg = api_settings.FORMAT_SUFFIX_KWARG
      if allowed:
          if len(allowed) == 1:
              allowed_pattern = allowed[0]
          else:
              allowed_pattern = '(%s)' % '|'.join(allowed)
keep keep keep keep replace keep keep keep keep keep
 docs, docs, docs, docs, docs, docs, docs 
rest_framework/urlpatterns.py