Json 如何用Argonaut解析映射[String，String]

我想分析如下内容：

{
          "OutputDocumentType": "receipt",
          "ParsedFields": {
            "smart_tags": "R°\nVul\nZe",
            "vendor": "",
            "vendor_terms": "",
            "vendor_warranty": "",
            "vendor_support": "",
            "vendor_url": "",
            "expense_category": "General Retail",
            "tracking_no": null,
            "carrier_name": null,
            "tracking_link": null,
            "tracking_status": null,
            "shipping_speed": null,
            "date_shipped": null,
            "date_estimated": null,
            "shipping_address_street_1": null,
            "shipping_address_street_2": null,
            "shipping_address_state_province": null,
            "shipping_address_city": null,
            "shipping_address_zip": null,
            "shipping_phone": null,
            "shipping_mobile": null,
            "shipping_fax": null,
            "account": "",
            "purchase_confirmation_no": "",
            "purchase_order_no": "",
            "purchase_time": "",
            "purchase_invoice_no": "",
            "purchase_invoice_date": "",
            "purchase_discounts": "",
            "subtotal_amount": "",
            "shipping_cost": "",
            "purchase_warranty": "",
            "transaction_id": "",
            "payment_address_street_1": "",
            "payment_address_street_2": "",
            "payment_address_city": "",
            "payment_address_state_province": "",
            "payment_address_zip": "",
            "payment_phone": "",
            "payment_mobile": "",
            "payment_fax": "",
            "receipt_date": "",
            "payment_type": "Cash",
            "total_amount": "$16.95"
          }
}

---

但是当我尝试跟踪时，它在

跟踪时失败，因为该值为
null
。如何使它只接受
null
值？
仅使映射成为
map[String，Option[String]]
即可解决它。
仅使映射成为
map[String，Option[String]]
即可解决它。
因此无法将
映射[String，String]
解析为
JSON对象，即
映射[String，ArgonautJsValue]
其中
ArgonautJsValue
表示：JSON、字符串、数字等？因此您无法将
Map[String，String]
解析为
JSON对象，即
Map[String，ArgonautJsValue]
其中
ArgonautJsValue
表示：JSON、字符串、数字等。？