batchDelete method
Deletes many messages by message ID.
Provides no guarantees that messages were not already deleted or even existed at all.
request - The metadata request object.
Request parameters:
userId - The user's email address. The special value me can be used to
indicate the authenticated user.
$fields - Selector specifying which fields to include in a partial
response.
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<void> batchDelete(
  BatchDeleteMessagesRequest request,
  core.String userId, {
  core.String? $fields,
}) async {
  final body_ = convert.json.encode(request);
  final queryParams_ = <core.String, core.List<core.String>>{
    if ($fields != null) 'fields': [$fields],
  };
  final url_ =
      'gmail/v1/users/' +
      commons.escapeVariable('$userId') +
      '/messages/batchDelete';
  await _requester.request(
    url_,
    'POST',
    body: body_,
    queryParams: queryParams_,
    downloadOptions: null,
  );
}