def METHOD_NAME(self, worker):
    # We have one task running right now.
    worker.future_job_mapping = {"job_id": "future"}
    job = Job(id, args=(10,))
    worker.storage.enqueue_job(job, QUEUE, Priority.REGULAR)
    job = worker.get_next_job()
    worker.future_job_mapping.clear()
    # Worker must not get this job since our regular worker is busy.
    assert job is None