Implement more of dart:mirrors

lib/runtime/dart_utils.js

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /* This library defines a set of general javascript utilities for us
  * by the Dart runtime.
 */
 
 var dart_utils =
   typeof module != "undefined" && module.exports || {};
@@ skipping 95 matching lines @@
     return copyTheseProperties(to, from, getOwnNamesAndSymbols(from));
   }
   dart_utils.copyProperties = copyProperties;
 
   /** Exports from one Dart module to another. */
   function export_(to, from, show, hide) {
     if (show == void 0) {
       show = getOwnNamesAndSymbols(from);
     }
     if (hide != void 0) {
-      var hideMap = new Map(hide);
+      var hideMap = new Set(hide);
       show = show.filter((k) => !hideMap.has(k));
     }
     return copyTheseProperties(to, from, show);
   }
   dart_utils.export = export_;
 
 })(dart_utils);