{
  "type": "object",
  "description": "The type of cargo item and the number of units.",
  "properties": {
    "symbol": {
      "type": "string"
    },
    "name": {
      "type": "string"
    },
    "units": {
      "type": "integer",
      "minimum": 1
    }
  },
  "required": [
    "symbol",
    "name",
    "units"
  ]
}