How to use the @hapi/statehood.Definitions function in @hapi/statehood

this.events = new Podium(internals.events);
        this.heavy = new Heavy(this.settings.load);
        this.instances = new Set();
        this.methods = new Methods(this);                                               // Server methods
        this.mime = new Mimos(this.settings.mime);
        this.onConnection = null;                                                       // Used to remove event listener on stop
        this.plugins = {};                                                              // Exposed plugin properties by name
        this.registrations = {};                                                        // Tracks plugin for dependency validation { name -> { version } }
        this.registring = 0;                                                            // > 0 while register() is waiting for plugin callbacks
        this.requestCounter = { value: internals.counter.min, min: internals.counter.min, max: internals.counter.max };
        this.router = new Call.Router(this.settings.router);
        this.phase = 'stopped';                                                         // 'stopped', 'initializing', 'initialized', 'starting', 'started', 'stopping', 'invalid'
        this.sockets = null;                                                            // Track open sockets for graceful shutdown
        this.actives = new WeakMap();                                                   // Active requests being processed
        this.started = false;
        this.states = new Statehood.Definitions(this.settings.state);
        this.toolkit = new Toolkit.Manager();

        this.extensionsSeq = 0;                                                         // Used to keep absolute order of extensions based on the order added across locations
        this.extensions = {
            server: {
                onPreStart: new Ext('onPreStart', this),
                onPostStart: new Ext('onPostStart', this),
                onPreStop: new Ext('onPreStop', this),
                onPostStop: new Ext('onPostStop', this)
            },
            route: {
                onRequest: new Ext('onRequest', this),
                onPreAuth: new Ext('onPreAuth', this),
                onCredentials: new Ext('onCredentials', this),
                onPostAuth: new Ext('onPostAuth', this),
                onPreHandler: new Ext('onPreHandler', this),