function Hub(client, scope, _version) {
        if (scope === void 0) { scope = new Scope(); }
        if (_version === void 0) { _version = API_VERSION; }
        this._version = _version;
        /** Is a {@link Layer}[] containing the client and scope */
        this._stack = [{}];
        this.getStackTop().scope = scope;
        if (client) {
            this.bindClient(client);
        }
    }
Creates a new instance of the hub, will push one {@link Layer} into the
internal stack on creation.

@param client bound to the hub.
@param scope bound to the hub.
@param version number, higher number means higher priority.