fetchAccessToken method
      
Future<FetchAccessTokenResponse> 
fetchAccessToken(
    
- FetchAccessTokenRequest request,
 - String accountConnector, {
 - String? $fields,
 
Fetches OAuth access token based on end user credentials.
request - The metadata request object.
Request parameters:
accountConnector - Required. The resource name of the AccountConnector
in the format projects / * /locations / * /accountConnectors / * .
Value must have pattern
^projects/\[^/\]+/locations/\[^/\]+/accountConnectors/\[^/\]+$.
$fields - Selector specifying which fields to include in a partial
response.
Completes with a FetchAccessTokenResponse.
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<FetchAccessTokenResponse> fetchAccessToken(
  FetchAccessTokenRequest request,
  core.String accountConnector, {
  core.String? $fields,
}) async {
  final body_ = convert.json.encode(request);
  final queryParams_ = <core.String, core.List<core.String>>{
    if ($fields != null) 'fields': [$fields],
  };
  final url_ =
      'v1/' +
      core.Uri.encodeFull('$accountConnector') +
      '/users:fetchAccessToken';
  final response_ = await _requester.request(
    url_,
    'POST',
    body: body_,
    queryParams: queryParams_,
  );
  return FetchAccessTokenResponse.fromJson(
    response_ as core.Map<core.String, core.dynamic>,
  );
}