code: function recursiveBundle(bundleExt, variables, errorCallback) {
  	return through2.obj(function (file, enc, cb) {
  		if (!checkFile(file, cb))
  			return;
  
  		// standart file push to callback
  		if (path.extname(file.path).toLowerCase() != bundleExt)
  			return cb(null, file);
  
  		// bundle file should be parsed
  		processBundleFile(file, bundleExt, variables, null, errorCallback)
  			.pipe(pushTo(this))
  			.on('end', cb);
  	});
  }
docs: recursively processes files and unwraps bundle files