private function backupCurrentVersion()
    {
        $this->fs->copy($this->currentInstallerFile, $this->currentInstallerBackupFile, true);
        $this->restorePreviousInstaller = true;

        return $this;
    }
private function backupCurrentVersion()
    {
        $this->fs->copy($this->currentInstallerFile, $this->currentInstallerBackupFile, true);
        $this->restorePreviousInstaller = true;

        return $this;
    }
private function backupCurrentVersion ( ) { $ this -> fs -> copy ( $ this -> currentInstallerFile , $ this -> currentInstallerBackupFile , true ) ; $ this -> restorePreviousInstaller = true ; return $ this ; }
Does a backup of the current version of the Symfony installer.

@return $this
Does a backup of the current version of the Symfony installer .