public function testRefund()
{
/**
* @var AopTradeRefundResponse $response
*/
$response = $this->gateway->refund(['biz_content' => ['refund_amount' => '10.01', 'out_trade_no' => '201609220542532413']])->send();
$this->assertArrayHasKey('alipay_trade_refund_response', $response->getData());
$this->assertFalse($response->isSuccessful());
}