old_contents: /*!
   * index
   * Version: 0.0.1
   * Date: 2017/05/19
   * https://github.com/nuintun/gulp-css
   *
   * This is licensed under the MIT License (MIT).
   * For details, see: https://github.com/nuintun/gulp-css/blob/master/LICENSE
   */
  
  'use strict';
  
  var util = require('./lib/util');
  var transform = require('./lib/transform');
  var concat = require('./lib/concat');
  var gutil = require('@nuintun/gulp-util');
  var duplexer = require('@nuintun/duplexer');
  
  /**
   * main
   * @param options
   * @returns {Duplexer}
   */
  function main(options) {
    var input = transform(options);
    var output = concat();
    var duplex = duplexer({ objectMode: true }, input, output);
  
    input.pipe(output);
  
    return duplex;
  }
  
  main.cwd = gutil.cwd;
  main.cache = util.cache;
  main.debug = util.debug;
  main.colors = gutil.colors;
  main.defaults = { plugins: gutil.plugins(require('./lib/plugins/index')) };
  
  /**
   * exports module
   */
  module.exports = main;
  
new_contents: /*!
   * index
   * Version: 0.0.1
   * Date: 2017/05/19
   * https://github.com/nuintun/gulp-css
   *
   * This is licensed under the MIT License (MIT).
   * For details, see: https://github.com/nuintun/gulp-css/blob/master/LICENSE
   */
  
  'use strict';
  
  var util = require('./lib/util');
  var transform = require('./lib/transform');
  var concat = require('./lib/concat');
  var gutil = require('@nuintun/gulp-util');
  var duplexer = require('@nuintun/duplexer');
  
  /**
   * main
   * @param options
   * @returns {Duplexer}
   */
  function main(options) {
    var input = transform(options);
    var output = concat();
    var duplex = duplexer({ objectMode: true }, input, output);
  
    input.pipe(output);
  
    return duplex;
  }
  
  main.cwd = gutil.cwd;
  main.cache = util.cache;
  main.debug = util.debug;
  main.print = util.print;
  main.colors = gutil.colors;
  main.defaults = { plugins: gutil.plugins(require('./lib/plugins/index')) };
  
  /**
   * exports module
   */
  module.exports = main;
  
subject: update files