I'm testing a class with PHPSpec which is going fine until I wanted to create a mock for a class that has static functions.
Class I'm testing:
<?php
namespace App\Service;
class PaymentService
{
    public function paymentVerification($orderId, array $data)
    {
        ...
        // Get the payment details
        $payment = \PayPal\Api\Payment::get($data['payKey'], $apiContext);
        ...
    }
}
PHPSpec class:
<?php
namespace App\Spec\Service;
use PhpSpec\ObjectBehavior;
use Prophecy\Argument;
class PaymentServiceSpec extends ObjectBehavior
{
    /**
     * @param \PayPal\API\Payment $payment
     */
    function it_should_return_false_when_the_payment_verification_failed($payment)
    {
        ...
        // This throws a PHP Fatal error:  Call to undefined method PhpSpec\Wrapper\Collaborator::get() in
        $payment::get(Argument::exact($data['payKey']), Argument::exact($apiContext))->shouldReturn(array('foobar'));
        ...
        $this->paymentVerification($orderId, $data)->shouldReturn(false);
    }
}
How can I mock \PayPal\Api\Payment::get($data['payKey'], $apiContext); ? Currently this throws a PHP Fatal error: Call to undefined method PhpSpec\Wrapper\Collaborator::get()
How can this be done correctly? Thanks in advance!