{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "OuterStruct",
  "type": "object",
  "properties": {
    "inner": {
      "anyOf": [
        {
          "$ref": "#/definitions/InnerStruct"
        },
        {
          "type": "null"
        }
      ]
    }
  },
  "definitions": {
    "InnerStruct": {
      "type": "array",
      "items": [
        {
          "type": "string"
        },
        {
          "type": "integer",
          "format": "int32"
        }
      ],
      "maxItems": 2,
      "minItems": 2
    }
  }
}