code: def buckets_list():
      """Implement the 'Buckets: list' API: return the Buckets in a project."""
      base_url = flask.url_for("gcs_index", _external=True)
      project = flask.request.args.get("project")
      if project is None or project.endswith("-"):
          raise error_response.ErrorResponse(
              "Invalid or missing project id in `Buckets: list`"
          )
      insert_magic_bucket(base_url)
      result = {"next_page_token": "", "items": []}
      for name, b in testbench_utils.all_buckets():
          result["items"].append(b.metadata)
      return testbench_utils.filtered_response(flask.request, result)
  
imports: import argparse
  import error_response
  import flask
  import gcs_bucket
  import gcs_object
  import json
  import os
  import re
  import testbench_utils
  import time
  import sys
  from werkzeug import serving
  from werkzeug.middleware.dispatcher import DispatcherMiddleware
label_desc: Use image node_id 10 for calling a global function with example usage: buckets_list() and returns: testbench_utils