json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "Ex",
      "description": "An Ex organism",
      "type": "object",
      "properties": {
          "modifier": {
              "description": "A modifier",
              "enum": [
                  "",
                  "blue"
              ]
          },
          "title": {
              "description": "Title of the pattern",
              "type": "string",
              "minLength": 3,
              "maxLength": 100
          },
          "links": {
              "description": "An array of links",
              "type": "array",
              "minItems": 1,
              "items": {
                  "type": "object",
                  "properties": {
                      "uri": {
                          "description": "the target uri",
                          "type": "string",
                          "pattern": "^[a-z]*$"
                      },
                      "text": {
                          "description": "The link text",
                          "type": "string"
                      }
                  }
              },
              "required": [
                  "uri",
                  "text"
              ],
              "additionalProperties": false
          },
          "buttons": {
              "description": "a boolean",
              "type": "boolean"
          }
      },
      "required": [
          "title",
          "links"
      ]
  }