{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "type": "object",
    "properties": {
        "variable": {
            "type": "object",
            "properties": {
                "datatype": {
                    "type": "object",
                    "properties": {
                        "basetype": {
                            "type": "string"
                        },
                        "conversion": {
                            "type": [
                                "null",
                                "string"
                            ]
                        }
                    }
                },
                "min": {
                    "type": [
                        "null",
                        "integer"
                    ]
                }
            },
            "required": [
                "datatype"
            ],
            "additionalProperties": true
        }
    },
    "required": [
        "variable"
    ],
    "additionalProperties": false
}