JobReleaseTask.withId(String id) Method

Set the ID can contain any combination of alphanumeric characters including hyphens and underscores and cannot contain more than 64 characters. If you do not specify this property, the Batch service assigns a default value of 'jobrelease'. No other task in the job can have the same ID as the Job Release task. If you try to submit a task with the same id, the Batch service rejects the request with error code TaskIdSameAsJobReleaseTask; if you are calling the REST API directly, the HTTP status code is 409 (Conflict).