BehaviorEvent

{
    "occurred_at": 0,
    "event_type": "recommend_home_impression",
    "properties": {
        "rec_session_id": "string",
        "item_ids": "1001,1002,1003",
        "position_indexes": "1,2,3",
        "module_position": "首页推荐商品区"
    }
}