json_schema: {
      "definitions": {
          "email": {
              "type": "string",
              "format": "email"
          },
          "user": {
              "required": [
                  "name",
                  "email"
              ],
              "type": "object",
              "properties": {
                  "name": {
                      "$ref": "#/definitions/name"
                  },
                  "email": {
                      "$ref": "#/definitions/email"
                  }
              }
          },
          "name": {
              "pattern": "^[a-zA-Z][- 'a-zA-Z0-9]+",
              "type": "string"
          }
      },
      "$schema": "http://json-schema.org/draft-04/schema#",
      "properties": {
          "email": {
              "$ref": "#/definitions/email"
          },
          "user": {
              "$ref": "#/definitions/user"
          },
          "name": {
              "$ref": "#/definitions/name"
          }
      },
      "required": [
          "email",
          "user",
          "name"
      ]
  }