json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "Data Retention",
      "description": "Defines the format for describing the retention policy of a data source",
      "type": "object",
      "properties": {
          "span": {
              "description": "The expected lifespan (in seconds) of a data object",
              "type": "integer",
              "minimum": 0
          }
      },
      "required": [
          "span"
      ]
  }