eZ\Publish\Core\FieldType\Image\IO\Legacy::getExternalPath PHP Method

    public function getExternalPath($internalId)
    {
        return $this->publishedIOService->getExternalPath($internalId);
    }

 public function testGetExternalPath()
 {
     $this->publishedIoServiceMock->expects($this->once())->method('getExternalPath')->with('var/test/storage/images/path/file.png')->will($this->returnValue('path/file.png'));
     self::assertEquals('path/file.png', $this->service->getExternalPath('var/test/storage/images/path/file.png'));
 }