implementation of JSON schema

 JSON Schema defines the media type "application/schema+json", a JSON
 based format for defining the structure of JSON data. JSON Schema
 provides a contract for what JSON data is required for a given
 application and how to interact with it. JSON Schema is intended to
 define validation, documentation, hyperlink navigation, and interaction
 control of JSON data.
 .
 This package provides a PHP library for validating JSON Structures
 against a given Schema.