allOf:
  - $ref: './BasicChart.yaml'
  - type: object
    properties:
      city_id:
        $ref: '../properties/city_id_nullable.yaml'
      city_name:
        $ref: '../properties/city_name_nullable.yaml'
example:
  chart_id: 'shazam_us_5678'
  name: 'Shazam Top Boston, US'
  city_id: '5678'
  city_name: 'New York'
  country_code: 'us'