[
  {
    "description": "refer to subschema by a unique name ($id)",
    "schema": {
      "type": "object",
      "properties": {
        "cars": {
          "type": "array",
          "items": {
            "$ref": "#car"
          }
        }
      },
      "definitions": {
        "car": {
          "$id": "#car",
          "type": "object",
          "properties": {
            "model": {
              "type": "string"
            }
          },
          "required": [
            "model"
          ]
        }
      }
    },
    "tests": [
      {
        "description": "invalid when element referenced by id is invalid",
        "data": {
          "cars": [
            {
            }
          ]
        },
        "valid": false
      },
      {
        "description": "valid when element referenced by id is valid",
        "data": {
          "cars": [
            {
              "model": "BMW"
            }
          ]
        },
        "valid": true
      }
    ]
  }
]