{
  "type": "object",
  "properties": {
    "action": {
      "type": "string",
      "enum": ["increase", "decrease"] 
    },
    "qty": {
      "type": ["string", "integer"],
      "pattern": "^[1-9][0-9]*$"
    }
  },
  "required": ["action", "qty"],
  "additionalProperties": true,
  "errorMessage": {
    "properties": {
      "action": "Action is required. It must be either 'increase' or 'decrease'",
      "qty": "Qty is invalid"
    }
  }
}