create method
      
Future<OrderTrackingSignal> 
create(
    
- OrderTrackingSignal request,
- String parent, {
- String? orderTrackingSignalId,
- String? $fields,
Creates new order tracking signal.
request - The metadata request object.
Request parameters:
parent - Required. The account of the business for which the order
signal is created. Format: accounts/{account}
Value must have pattern ^accounts/\[^/\]+$.
orderTrackingSignalId - Output only. The ID that uniquely identifies
this order tracking signal.
$fields - Selector specifying which fields to include in a partial
response.
Completes with a OrderTrackingSignal.
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<OrderTrackingSignal> create(
  OrderTrackingSignal request,
  core.String parent, {
  core.String? orderTrackingSignalId,
  core.String? $fields,
}) async {
  final body_ = convert.json.encode(request);
  final queryParams_ = <core.String, core.List<core.String>>{
    if (orderTrackingSignalId != null)
      'orderTrackingSignalId': [orderTrackingSignalId],
    if ($fields != null) 'fields': [$fields],
  };
  final url_ =
      'ordertracking/v1/' +
      core.Uri.encodeFull('$parent') +
      '/orderTrackingSignals';
  final response_ = await _requester.request(
    url_,
    'POST',
    body: body_,
    queryParams: queryParams_,
  );
  return OrderTrackingSignal.fromJson(
    response_ as core.Map<core.String, core.dynamic>,
  );
}