public function testOnlyAddKeyOnAcfUrl()
{
// Make key available in the ENVIRONMENT
putenv(self::KEY_ENV_VARIABLE . '=KEY');
// Mock an Event
$event = $this->getMockBuilder('Composer\\Plugin\\PreFileDownloadEvent')->disableOriginalConstructor()->setMethods(['getProcessedUrl', 'getRemoteFilesystem', 'setRemoteFilesystem'])->getMock();
$event->expects($this->once())->method('getProcessedUrl')->willReturn('another-url');
$event->expects($this->never())->method('getRemoteFilesystem');
$event->expects($this->never())->method('setRemoteFilesystem');
// Call addKey
$plugin = new Plugin();
$plugin->addKey($event);
}