text: 'use strict';
  
  var through = require('through2');
  
  module.exports = function(options) {
    return through.obj(function (file, enc, cb) {
      var str = file.contents.toString();
      str += 'aaa\n';
  
      // var err = new Error('foo');
      // err.plugin = 'a';
      // this.emit('error', err);
      // return cb(err);
  
      file.contents = new Buffer(str);
      this.push(file);
      cb();
    });
  };
  