list method
List custom data sources to which the user has access.
Request parameters:
accountId - Account Id for the custom data sources to retrieve.
Value must have pattern \d+.
webPropertyId - Web property Id for the custom data sources to retrieve.
Value must have pattern UA-(\d+)-(\d+).
maxResults - The maximum number of custom data sources to include in
this response.
startIndex - A 1-based index of the first custom data source to
retrieve. Use this parameter as a pagination mechanism along with the
max-results parameter.
$fields - Selector specifying which fields to include in a partial
response.
Completes with a CustomDataSources.
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<CustomDataSources> list(
  core.String accountId,
  core.String webPropertyId, {
  core.int? maxResults,
  core.int? startIndex,
  core.String? $fields,
}) async {
  final queryParams_ = <core.String, core.List<core.String>>{
    if (maxResults != null) 'max-results': ['${maxResults}'],
    if (startIndex != null) 'start-index': ['${startIndex}'],
    if ($fields != null) 'fields': [$fields],
  };
  final url_ =
      'management/accounts/' +
      commons.escapeVariable('$accountId') +
      '/webproperties/' +
      commons.escapeVariable('$webPropertyId') +
      '/customDataSources';
  final response_ = await _requester.request(
    url_,
    'GET',
    queryParams: queryParams_,
  );
  return CustomDataSources.fromJson(
    response_ as core.Map<core.String, core.dynamic>,
  );
}