code: function _writeFile(i_sFilename, i_oFile, i_oCallback) {
      var l_sFilename = i_sFilename,
          l_oBuffer = new Buffer(i_oFile.fileData); // filedata is Uint8Array
      fs.writeFile(l_sFilename, l_oBuffer, function(err) {
          if (err) {
              console.log("Error writting file ", err);
              l_sFilename = null;
          }
          i_oCallback(l_sFilename);
      });
  }
docs: ==============================================================================