Formatter/YamlFormatter.php
public function addHeader(SplFileInfo $file, $header)
    {
        $content = file_get_contents($file->getRealPath());
        $content = $header.$content;
        file_put_contents($file->getRealPath(), $content);
    }
public function addHeader(SplFileInfo $file, $header)
    {
        $content = file_get_contents($file->getRealPath());
        $content = $header.$content;
        file_put_contents($file->getRealPath(), $content);
    }
{@inheritdoc}