:param key:
        :param value:

def set_tag(self, key, value):
        """
        :param key:
        :param value:
        """
        with self.update_lock:
            if key == ext_tags.SAMPLING_PRIORITY and not self._set_sampling_priority(value):
                return self
            if self.is_sampled():
                tag = thrift.make_tag(
                    key=key,
                    value=value,
                    max_length=self.tracer.max_tag_value_length, )
                self.tags.append(tag)
        return self