{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "title": "Standing instance",
    "type": "object",
    "required": ["positions"],
    "properties": {
        "positions": {
            "anyOf": [
                { "type": "integer", "maximum": 20, "description": "this is a desc"},
                { "type": "boolean", "description": "this is a desc" }]
        }
    },
    "additionalProperties": false
}