docs: def fetch(opts):
      """
      Create a local mirror of one or more resources.
      """
      resources = _load(opts.resources, opts.output_dir)
      if opts.all:
          opts.resource_names = ALL
      reporthook = None if opts.quiet else lambda name: print('Fetching {}...'.format(name))
      if opts.verbose:
          backend.VERBOSE = True
      _fetch(resources, opts.resource_names, opts.mirror_url, opts.force, reporthook)
      return verify(opts)