list method
Lists the Backups for a given BackupPlan.
Request parameters:
parent - Required. The BackupPlan that contains the Backups to list.
Format: projects / * /locations / * /backupPlans / * 
Value must have pattern
^projects/\[^/\]+/locations/\[^/\]+/backupPlans/\[^/\]+$.
filter - Optional. Field match expression used to filter the results.
orderBy - Optional. Field by which to sort the results.
pageSize - Optional. The target number of results to return in a single
response. If not specified, a default value will be chosen by the service.
Note that the response may include a partial list and a caller should only
rely on the response's next_page_token to determine if there are more
instances left to be queried.
pageToken - Optional. The value of next_page_token received from a
previous ListBackups call. Provide this to retrieve the subsequent page
in a multi-page list of results. When paginating, all other parameters
provided to ListBackups must match the call that provided the page
token.
$fields - Selector specifying which fields to include in a partial
response.
Completes with a ListBackupsResponse.
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<ListBackupsResponse> list(
  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') + '/backups';
  final response_ = await _requester.request(
    url_,
    'GET',
    queryParams: queryParams_,
  );
  return ListBackupsResponse.fromJson(
      response_ as core.Map<core.String, core.dynamic>);
}