json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "Users schema based on JSON API",
      "type": "object",
      "required": [
          "data"
      ],
      "data": {
          "description": "List of user resources.",
          "type": "array",
          "items": {
              "type": "object",
              "required": [
                  "type",
                  "id"
              ],
              "properties": {
                  "type": {
                      "type": "string"
                  },
                  "id": {
                      "type": "integer"
                  },
                  "attributes": {
                      "required": [
                          "first-name",
                          "last-name",
                          "email",
                          "authentication-token"
                      ],
                      "properties": {
                          "first-name": {
                              "type": "string"
                          },
                          "last-name": {
                              "type": "string"
                          },
                          "email": {
                              "type": "string"
                          },
                          "authentication-token": {
                              "type": "string"
                          },
                          "created-at": {
                              "type": "string",
                              "format": "date-time"
                          },
                          "updated-at": {
                              "type": "string",
                              "format": "date-time"
                          }
                      }
                  }
              }
          },
          "_uniqueItems": true
      },
      "properties": {
          "data": {
              "$ref": "#/data"
          }
      }
  }