Example of using "allOf" to make JSON Schema mixins

mixinSchema.json

{
  "definitions": {
    "nameMixin": {
      "type": "object",
      "properties": {
        "nameFirst": {"type": "string"},
        "nameLast": {"type": "string"}
      },
      "required": ["nameFirst", "nameLast"]
    },
    "person": {
      "allOf": [
        {"$ref": "/definitions/nameMixin"},
        {
          "type": "object",
          "properties": {
            "age": {"type": "number"}
          },
          "required": ["age"]
        }
      ]
    }
  }
}

Nice. I tried the same idea. The only thing to overcome is how to combine this successfully with { "additionalProperties": false }.