How to use the taskgraph.util.taskcluster.list_artifacts function in taskgraph

rev=rev,
            tree=tree,
            product=artifact_job_class.product,
            job=job,
        )
        self.log(logging.INFO, 'artifact',
                 {'namespace': namespace},
                 'Searching Taskcluster index with namespace: {namespace}')
        try:
            taskId = find_task_id(namespace)
        except KeyError:
            # Not all revisions correspond to pushes that produce the job we
            # care about; and even those that do may not have completed yet.
            raise ValueError('Task for {namespace} does not exist (yet)!'.format(namespace=namespace))

        return taskId, list_artifacts(taskId)

def install_from_task(self, taskId, distdir):
        artifacts = list_artifacts(taskId)

        urls = []
        for artifact_name in self._artifact_job.find_candidate_artifacts(artifacts):
            # We can easily extract the task ID from the URL.  We can't easily
            # extract the build ID; we use the .ini files embedded in the
            # downloaded artifact for this.
            url = get_artifact_url(taskId, artifact_name)
            urls.append(url)
        if not urls:
            raise ValueError('Task {taskId} existed, but no artifacts found!'.format(taskId=taskId))
        for url in urls:
            if self.install_from_url(url, distdir):
                return 1
        return 0