old_contents: define([
      './stream',
      '../functional/once',
      '../functional/noop'
  ], function(Stream, once, noopf) {
      'use strict';
  
      return once(function noop() {
          return new Stream(noopf);
      })
  });
  
new_contents: define([
      './stream',
      '../functional/once',
      '../functional/noop'
  ], function(Stream, once, noop) {
      'use strict';
  
      return once(function() {
          return new Stream(noop);
      })
  });
  
subject: Simplify noop stream