pkg/docgen: sort output files

pkg/docgen/lib/src/models.dart

 // Copyright (c) 2014, 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.
 
 library docgen.models;
 
 import 'dart:io';
 
 import 'package:markdown/markdown.dart' as markdown;
 
@@ skipping 379 matching lines @@
     var contents = markdown.markdownToHtml(readme
       .readAsStringSync(), linkResolver: linkResolver,
       inlineSyntaxes: MARKDOWN_SYNTAXES);
     return contents;
   }
 
   String get packagePrefix => packageName == null || packageName.isEmpty ?
       '' : '$packageName/';
 
   Map get previewMap {
-    var basic = super.previewMap;
-    basic['packageName'] = packageName;
+    var map = {'packageName': packageName};
+    map.addAll(super.previewMap);
     if (packageIntro != null) {
-      basic['packageIntro'] = packageIntro;
+      map['packageIntro'] = packageIntro;
     }
-    return basic;
+    return map;
   }
 
   String get name => docName;
 
   String get docName {
     return dart2js_util.qualifiedNameOf(mirror).replaceAll('.','-');
   }
 
   /// Checks if the given name is a key for any of the Class Maps.
   bool containsKey(String name) =>
@@ skipping 648 matching lines @@
         .map((e) => originalMirror.getField(e.simpleName).reflectee)
         .where((e) => e != null)
         .toList();
   }
 
   Map toMap() => {
     'name': getDocgenObject(mirror, owningLibrary).docName,
     'parameters': parameters
   };
 }