{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "type": "object",
    "properties": {
        "title": {
            "type": "string",
            "maxLength": 30
        },
        "choices": {
            "type": "array",
            "items": {
                "type": "string",
                "maxLength": 30
            },
            "minItems": 1,
            "_uniqueItems": true
        }
    },
    "required": [
        "title",
        "choices"
    ],
    "additionalProperties": false
}