json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "id": "https://raw.githubusercontent.com/washingtonpost/ans-schema/master/src/main/resources/schema/ans/v0_4/headlines.json",
      "title": "A headlines key-value set.",
      "description": "A key-value group of headlines. Key is used to describe context in which a certain value should be used as the headline.",
      "type": "object",
      "properties": {
          "default": {
              "type": "string"
          }
      },
      "patternProperties": {
          ".*": {
              "type": "string"
          }
      },
      "required": [
          "default"
      ]
  }