GetItemOffersBatch may need updated serialization for request parameters

[nomuramasanori]

Hi,

First of all, thank you for maintaining this library. It has been very useful for our Amazon SP-API integration.

ProductPricing.GetItemOffersBatch started failing recently with the following error:

Requested MarketplaceId is invalid, unsupported, or does not exist.

I get error in case of using the following parameter.

{
  "requests": [
    {
      "uri": "/products/pricing/v0/items/XXXXXXXXXX/offers",
      "method": "GET",
      "queryParams": {
        "MarketplaceId": "XXXXXXXXXXXXXX",
        "CustomerType": "Consumer",
        "ItemCondition": "New"
      }
    },
    {
      "uri": "/products/pricing/v0/items/XXXXXXXXXX/offers",
      "method": "GET",
      "queryParams": {
        "MarketplaceId": "XXXXXXXXXXXXXX",
        "CustomerType": "Consumer",
        "ItemCondition": "New"
      }
    }
  ]
}

On the other hand, the following method will lead to success.

{
  "requests": [
    {
      "uri": "/products/pricing/v0/items/XXXXXXXXXX/offers",
      "method": "GET",
      "MarketplaceId": "XXXXXXXXXXXXXX",
      "CustomerType": "Consumer",
      "ItemCondition": "New"
    },
    {
      "uri": "/products/pricing/v0/items/XXXXXXXXXX/offers",
      "method": "GET",
      "MarketplaceId": "XXXXXXXXXXXXXX",
      "CustomerType": "Consumer",
      "ItemCondition": "New"
    }
  ]
}

I would appreciate it if you could take a look when you have a chance.

[abuzuhri]

Hi @nomuramasanori — this is the same issue as #931, fixed in commit c8e33b2 (PR #929).