Extract tags from the given object

        :param Any obj: Object to use as context
        :return: Tags to add on span
        :rtype: dict

def extract_tags(cls, obj):
        """ Extract tags from the given object

        :param Any obj: Object to use as context
        :return: Tags to add on span
        :rtype: dict
        """
        return dict(
            [("request.{}".format(attr), obj.get(attr, None)) for attr in
             cls.TAGS]
        )