{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "$ref": "#/definitions/TestNullable",
  "definitions": {
    "TestNullable": {
      "required": ["child1"],
      "properties": {
        "child1": {
          "oneOf": [
            {
              "type": "string"
            },
            {
              "type": "null"
            }
          ]
        }
      },
      "additionalProperties": false,
      "type": "object"
    }
  }
}
