fetchUsable method
FetchUsableBackupVaults lists usable BackupVaults in a given project and location.
Usable BackupVault are the ones that user has backupdr.backupVaults.get permission.
Request parameters:
parent - Required. The project and location for which to retrieve
backupvault stores information, in the format
'projects/{project_id}/locations/{location}'. In Cloud Backup and DR,
locations map to Google Cloud regions, for example us-central1. To
retrieve backupvault stores for all locations, use "-" for the
'{location}' value.
Value must have pattern ^projects/\[^/\]+/locations/\[^/\]+$.
filter - Optional. Filtering results.
orderBy - Optional. Hint for how to order the results.
pageSize - Optional. Requested page size. Server may return fewer items
than requested. If unspecified, server will pick an appropriate default.
pageToken - Optional. A token identifying a page of results the server
should return.
$fields - Selector specifying which fields to include in a partial
response.
Completes with a FetchUsableBackupVaultsResponse.
Completes with a commons.ApiRequestError if the API endpoint returned an error.
If the used http.Client completes with an error when making a REST call,
this method will complete with the same error.
Implementation
async.Future<FetchUsableBackupVaultsResponse> fetchUsable(
  core.String parent, {
  core.String? filter,
  core.String? orderBy,
  core.int? pageSize,
  core.String? pageToken,
  core.String? $fields,
}) async {
  final queryParams_ = <core.String, core.List<core.String>>{
    if (filter != null) 'filter': [filter],
    if (orderBy != null) 'orderBy': [orderBy],
    if (pageSize != null) 'pageSize': ['${pageSize}'],
    if (pageToken != null) 'pageToken': [pageToken],
    if ($fields != null) 'fields': [$fields],
  };
  final url_ =
      'v1/' + core.Uri.encodeFull('$parent') + '/backupVaults:fetchUsable';
  final response_ = await _requester.request(
    url_,
    'GET',
    queryParams: queryParams_,
  );
  return FetchUsableBackupVaultsResponse.fromJson(
      response_ as core.Map<core.String, core.dynamic>);
}