1. @override
Future<int> handle()

Handles the command input.

Override this method to perform actions for this command.

Return value is the value returned to the command line operation. Return 0 for success.

Source 

@override
Future<int> handle() async {
  displayInfo("Available templates:");
  displayProgress("");
  displayProgress("default - an empty Aqueduct application");
  displayProgress("db - an Aqueduct application with a database connection and data model");
  displayProgress("db_and_auth - an Aqueduct application with a database connection, data model and OAuth 2.0 endpoints");
  return 0;
}