json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "Amount",
      "description": "PayPal amount json schema",
      "type": "object",
      "properties": {
          "currency": {
              "description": "3-letter currency code. PayPal does not support all currencies.",
              "type": "string",
              "minLength": 3,
              "maxLength": 3
          },
          "total": {
              "description": "Total amount charged from the payer to the payee. In case of a refund, this is the refunded amount to the original payer from the payee. 10 characters max with support for 2 decimal places.",
              "type": "string",
              "maxLength": 10
          },
          "details": {
              "type": "object",
              "properties": {
                  "shipping": {
                      "type": "string",
                      "maxLength": 10
                  },
                  "subtotal": {
                      "type": "string",
                      "maxLength": 10
                  },
                  "tax": {
                      "type": "string",
                      "maxLength": 10
                  },
                  "handling_fee": {
                      "type": "string"
                  },
                  "insurance": {
                      "type": "string"
                  },
                  "shipping_discount": {
                      "type": "string"
                  }
              },
              "additionalProperties": false
          }
      },
      "required": [
          "currency",
          "total"
      ]
  }