def METHOD_NAME(self, task_ins: TaskIns) -> Optional[UUID]:
    """Store one TaskIns."""
    # Validate task
    errors = validate_task_ins_or_res(task_ins)
    if any(errors):
        log(ERROR, errors)
        return None
    # Create task_id, created_at and ttl
    task_id = uuid4()
    created_at: datetime = now()
    ttl: datetime = created_at + timedelta(hours=24)
    # Store TaskIns
    task_ins.task_id = str(task_id)
    task_ins.task.created_at = created_at.isoformat()
    task_ins.task.ttl = ttl.isoformat()
    self.task_ins_store[task_id] = task_ins
    # Return the new task_id
    return task_id