PayPal\Api\Order::setAmount PHP Method

    public function setAmount($amount)
    {
        $this->amount = $amount;
        return $this;
    }

 public static function createOrder()
 {
     $order = new Order();
     $order->setId(self::$id);
     $order->setCreateTime(self::$createTime);
     $order->setUpdateTime(self::$updateTime);
     $order->setState(self::$state);
     $order->setAmount(AmountTest::createAmount());
     return $order;
 }