Cloudformation to Update Existing AWS Glue Crawler for DocumentDB Collections

I'm trying to update an existing AWS Glue Crawler for a DocumentDB instance. Given that it won't take a wildcard to add all the collections to the crawler I'm looking for an easy way to add several collections to the crawler via Cloudformation.

I'm running into errors trying to get the syntax built out for this. This is what I have thus far and its not working:

"Resources":
  "UpdateCrawler":
    "Type": AWS::Glue::Crawler
    "Properties": {
      "Name": testDB
      "MongoDBTarget":
          "Database": testDB      
      "Update":
        "AddDatasources":
          - DatabaseName: testDB
            "Tables":
              - TableName: testDB/CustomerOrders
              - TableName: testDB/ShippingInformation

"Outputs":
  "CrawlerArn":
    "Value": !Ref UpdateCrawler
    }