error(e = undefined) {
		            if (!IsWritableStreamDefaultController(this)) {
		                throw defaultControllerBrandCheckException$2('error');
		            }
		            const state = this._controlledWritableStream._state;
		            if (state !== 'writable') {
		                // The stream is closed, errored or will be soon. The sink can't do anything useful if it gets an error here, so
		                // just treat it as a no-op.
		                return;
		            }
		            WritableStreamDefaultControllerError(this, e);
		        }
Check if `obj` is an instance of Request.

@param  {*} object
@return {boolean}