If there is no current instance, create one. This will run the job on an immediate single-run schedule. If there is a current instance and the "requested_status" parameter is given, then the system will attempt to change the status of the current instance to the requested status. This is not guaranteed as there a number of conditions which might prevent an instance from, e.g. achieving a running state when currently "suspended". The client should poll the current instance with a GET to determine whether the requested state has been achieved.