{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "definitions": {
    "pets": {
      "type": "object",
      "properties": {
        "amount": {
          "type": "string"
        },
        "@amount": {
          "type": "integer"
        }
      },
      "required": [ "amount" ]
    }
  }
}