docs: function transformAllFiles(transform, flush) {
    var files = [];
  
    return through.obj(
      function(file, enc, cb) {
        if (file.isStream()) {
          this.emit('error', new gutil.PluginError(PLUGIN_NAME, 'Streams are not supported!'));
          return cb();
        }
  
        if (file.isBuffer()) {
          if (transform) transform.call(this, file, enc);
        }
  
        files.push(file);
        cb();
      },
      function(cb) {
        if (flush) files = flush.call(this, files);
        for (var i = 0; i < files.length; ++i) {
          this.push(files[i]);
        }
        cb();
      }
    );
  }