Celery tasks chain from groovy

celery-message.groovy

def sendThenApproveOrder(orderId, dateString) {
    def config = grailsApplication.config
    def refkey = config.co.mias.forms.services.refkey.toString()
    def message = [
        'args': [refkey, orderId, dateString],
        'task': 'milery.task.order.send_new_order',
        'id': randomUUID() as String,
        'callbacks': [
            [
                'immutable': true,
                'args': [refkey, orderId, dateString],
                'task': 'milery.task.order.approve_order',
                'id': randomUUID() as String,
                'options': [:]
            ]
        ]
    ] as JSON
    
    messageService.send(message.toString())
    log.info 'sendThenApproveOrder: ' + orderId + ', ' + dateString
}