Function has

core/src/BaseExchange.ts:451–456

* Capability map derived automatically from method overrides at runtime. * Exchanges do NOT need to declare this manually -- if a subclass overrides * a method (and the override does not throw "not supported"), it is `true`. * To mark a capability as `'emulated'`, add its key to `emul

()

     * To mark a capability as `'emulated'`, add its key to `emulatedCapabilities`.
     */
    get has(): ExchangeHas {
        if (!this._has) {
            this._has = this._deriveCapabilities();
        }
        return this._has;
    }
    private _has?: ExchangeHas;

    /**