list method
Lists all the custom channels available in an ad client.
Request parameters:
parent - Required. The ad client which owns the collection of custom
channels. Format: accounts/{account}/adclients/{adclient}
Value must have pattern ^accounts/\[^/\]+/adclients/\[^/\]+$.
pageSize - The maximum number of custom channels to include in the
response, used for paging. If unspecified, at most 10000 custom channels
will be returned. The maximum value is 10000; values above 10000 will be
coerced to 10000.
pageToken - A page token, received from a previous ListCustomChannels
call. Provide this to retrieve the subsequent page. When paginating, all
other parameters provided to ListCustomChannels must match the call that
provided the page token.
$fields - Selector specifying which fields to include in a partial
response.
Completes with a ListCustomChannelsResponse.
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<ListCustomChannelsResponse> list(
  core.String parent, {
  core.int? pageSize,
  core.String? pageToken,
  core.String? $fields,
}) async {
  final queryParams_ = <core.String, core.List<core.String>>{
    if (pageSize != null) 'pageSize': ['${pageSize}'],
    if (pageToken != null) 'pageToken': [pageToken],
    if ($fields != null) 'fields': [$fields],
  };
  final url_ = 'v2/' + core.Uri.encodeFull('$parent') + '/customchannels';
  final response_ = await _requester.request(
    url_,
    'GET',
    queryParams: queryParams_,
  );
  return ListCustomChannelsResponse.fromJson(
    response_ as core.Map<core.String, core.dynamic>,
  );
}