private function getGitHttpBackendCommand()
 {
     $command = new Git_HTTP_CommandCentos5GitHttpBackend();
     if (Git_Exec::isGit19Installed()) {
         $command = new Git_HTTP_CommandSCL19GitHttpBackend();
     } elseif (is_file('/usr/libexec/git-core/git-http-backend')) {
         $command = new Git_HTTP_CommandCentos6GitHttpBackend();
     }
     return $command;
 }