anchor.diff:      StringLiteral uri = pop();
       List<Annotation> metadata = pop();
       assert(metadata == null);
  -    // TODO(paulberry): capture doc comments.
  +    // TODO(paulberry): capture doc comments.  See dartbug.com/28851.
       Comment comment = null;
       push(ast.exportDirective(comment, metadata, toAnalyzerToken(exportKeyword),
           uri, configurations, combinators, toAnalyzerToken(semicolon)));
  
positive.code:     assert(modifiers == null);
      analyzer.Token externalKeyword = null;
      List<Annotation> metadata = pop();
      // TODO(paulberry): capture doc comments.
      Comment comment = null;
      push(ast.functionDeclaration(
          comment,
  
negative.code:     SimpleIdentifier name = pop();
      TypeAnnotation returnType = pop();
      List<Annotation> metadata = pop();
      // TODO(paulberry): capture doc comments.  See dartbug.com/28851.
      Comment comment = null;
      push(ast.functionTypeAlias(
          comment,
  