/**
* Creates a new package file.
*
* @param string|null $packageName The package name. Optional.
* @param string|null $path The path where the file is stored or
* `null` if this configuration is not
* stored on the file system.
*
* @throws InvalidArgumentException If the name/path is not a string or empty.
*/
public function __construct($packageName = null, $path = null)
{
Assert::nullOrPackageName($packageName);
Assert::nullOrAbsoluteSystemPath($path);
$this->path = $path;
$this->packageName = $packageName;
}