              else:
                  field = self.get_field(model_field)
  
              if field:
                  field.initialize(parent=self)
                  ret[model_field.name] = field
  
          return ret
  
      def get_pk_field(self, model_field):
 
</s> remove             field.initialize(parent=self)
 </s> add             field.initialize(parent=self, field_name=key) </s> remove     def initialize(self, parent):
 </s> add     def initialize(self, parent, field_name): </s> remove         self.read_only = self.default_read_only
 </s> add         self.read_only = kwargs.pop('read_only', self.default_read_only)

    def initialize(self, parent, field_name):
        super(RelatedField, self).initialize(parent, field_name)
        if self.queryset is None and not self.read_only:
            try:
                manager = getattr(self.parent.opts.model, self.source or field_name)
                if hasattr(manager, 'related'):  # Forward
                    self.queryset = manager.related.model._default_manager.all()
                else:  # Reverse
                    self.queryset = manager.field.rel.to._default_manager.all()
            except:
                raise
                msg = ('Serializer related fields must include a `queryset`' +
                       ' argument or set `read_only=True')
                raise Exception(msg) </s> remove     blog_post_url = serializers.HyperlinkedRelatedField(source='blog_post', view_name='blogpost-detail', queryset=BlogPost.objects.all())
 </s> add     blog_post_url = serializers.HyperlinkedRelatedField(source='blog_post', view_name='blogpost-detail') </s> remove class BlogPostCommentSerializer(serializers.Serializer):
 </s> add class BlogPostCommentSerializer(serializers.ModelSerializer):
                field.initialize(parent=self, field_name=model_field.name)
              else:
                  field = self.get_field(model_field)
  
              if field:
                field.initialize(parent=self, field_name=model_field.name)
                  ret[model_field.name] = field
  
          return ret
  
      def get_pk_field(self, model_field):
keep keep keep keep replace keep keep keep keep keep
 `queryset` argument is now optional on writable model fields. 
rest_framework/serializers.py