json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "type": "object",
      "properties": {
          "headline": {
              "type": "object",
              "required": [
                  "htmlText"
              ],
              "properties": {
                  "htmlText": {
                      "type": "string",
                      "description": "The HTML headline content."
                  }
              }
          },
          "intro": {
              "type": "object",
              "properties": {
                  "htmlText": {
                      "type": "string",
                      "description": "Additional introductory HTML text to be shown below the headline."
                  }
              }
          }
      }
  }