              # Set content type if form contains a non-empty CONTENTTYPE_PARAM field
              content_type = None
              if self.CONTENTTYPE_PARAM and request.POST.get(self.CONTENTTYPE_PARAM, None):
                  content_type = request.POST.get(self.CONTENTTYPE_PARAM, None)
                  request.META['CONTENT_TYPE'] = content_type
  
              return (content_type, request.POST[self.CONTENT_PARAM])
          else:
              return (content_type, request.raw_post_data)
 
</s> remove                 if isinstance(attr_value, list):
                    flatdata[key] = attr_value[0]
 </s> add                 if val_list:
                    flatdata[key] = val_list[0] </s> remove         for key, attr_value in data.items():
            if self.is_a_list(key):
                if isinstance(attr_value, list):
                    flatdata[key] = attr_value
                else:
                    flatdata[key] = [attr_value]
 </s> add         for key, val_list in data.items():
            if self.is_a_list(key, val_list):
                flatdata[key] = val_list </s> remove                     flatdata[key] = attr_value 
 </s> add                     # If the list is empty, but the parameter is not a list,
                    # we strip this parameter.
                    data.pop(key) </s> remove         for key in filter(lambda k: self.is_a_list(k), data):
            self.remove_empty_val(data[key])
 </s> add 
                request.META['CONTENT_TYPE'] = content_type # TODO : VERY BAD, avoid modifying original request.
              # Set content type if form contains a non-empty CONTENTTYPE_PARAM field
              content_type = None
              if self.CONTENTTYPE_PARAM and request.POST.get(self.CONTENTTYPE_PARAM, None):
                  content_type = request.POST.get(self.CONTENTTYPE_PARAM, None)
                request.META['CONTENT_TYPE'] = content_type # TODO : VERY BAD, avoid modifying original request.
  
              return (content_type, request.POST[self.CONTENT_PARAM])
          else:
              return (content_type, request.raw_post_data)
keep keep keep keep replace keep keep keep keep
 documentation + tests + debugging for formparsers 
djangorestframework/content.py