docs: function processFileByModifiedTime(stream, firstPass, basePath, file, cache) {
    var newTime = file.stat && file.stat.mtime;
    var filePath = basePath ? path.relative(basePath, file.path) : file.path;
    var oldTime = cache[filePath];
  
    cache[filePath] = newTime.getTime();
  
    if ((!oldTime && firstPass) || (oldTime && oldTime !== newTime.getTime())) {
      stream.push(file);
    }
  }