Improve type information and minor clean up

pkg/analyzer/lib/dart/ast/ast.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.
 
 /**
  * Defines the AST model. The AST (Abstract Syntax Tree) model describes the
  * syntactic (as opposed to semantic) structure of Dart code. The semantic
  * structure of the code is modeled by the
  * [element model](../element/element.dart).
  *
@@ skipping 580 matching lines @@
    * Use the given [visitor] to visit this node. Return the value returned by
    * the visitor as a result of visiting this node.
    */
   dynamic/*=E*/ accept/*<E>*/(AstVisitor/*<E>*/ visitor);
 
   /**
    * Return the most immediate ancestor of this node for which the [predicate]
    * returns `true`, or `null` if there is no such ancestor. Note that this node
    * will never be returned.
    */
-  AstNode getAncestor(Predicate<AstNode> predicate);
+  AstNode/*=E*/ getAncestor/*<E extends AstNode>*/(
+      Predicate<AstNode> predicate);
 
   /**
    * Return the value of the property with the given [name], or `null` if this
    * node does not have a property with the given name.
    */
-  Object getProperty(String name);
+  Object/*=E*/ getProperty/*<E>*/(String name);
 
   /**
    * Set the value of the property with the given [name] to the given [value].
    * If the value is `null`, the property will effectively be removed.
    */
   void setProperty(String name, Object value);
 
   /**
    * Return a textual description of this node in a form approximating valid
    * source. The returned string will not be valid source primarily in the case
@@ skipping 7621 matching lines @@
   /**
    * Return the 'yield' keyword.
    */
   Token get yieldKeyword;
 
   /**
    * Return the 'yield' keyword to the given [token].
    */
   void set yieldKeyword(Token token);
 }