Fix hints

pkg/analyzer/lib/src/generated/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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.ast;
 
 import 'dart:collection';
@@ skipping 16307 matching lines @@
       }
       parent = access.parent;
       target = access;
     }
     // skip label
     if (parent is Label) {
       return false;
     }
     // analyze usage
     if (parent is AssignmentExpression) {
-      AssignmentExpression expr = parent as AssignmentExpression;
-      if (identical(expr.leftHandSide, target) &&
-          expr.operator.type == TokenType.EQ) {
+      if (identical(parent.leftHandSide, target) &&
+          parent.operator.type == TokenType.EQ) {
         return false;
       }
     }
     if (parent is ForEachStatement) {
-      ForEachStatement stmt = parent as ForEachStatement;
-      if (identical(stmt.identifier, target)) {
+      if (identical(parent.identifier, target)) {
         return false;
       }
     }
     return true;
   }
 
   /**
    * Return `true` if this expression is computing a left-hand value.
    *
    * Note that [inGetterContext] and [inSetterContext] are not opposites, nor
@@ skipping 16 matching lines @@
     } else if (parent is PropertyAccess) {
       PropertyAccess access = parent as PropertyAccess;
       if (identical(access.target, this)) {
         return false;
       }
       parent = access.parent;
       target = access;
     }
     // analyze usage
     if (parent is PrefixExpression) {
-      return (parent as PrefixExpression).operator.type.isIncrementOperator;
+      return parent.operator.type.isIncrementOperator;
     } else if (parent is PostfixExpression) {
       return true;
     } else if (parent is AssignmentExpression) {
-      return identical((parent as AssignmentExpression).leftHandSide, target);
+      return identical(parent.leftHandSide, target);
     } else if (parent is ForEachStatement) {
-      return identical((parent as ForEachStatement).identifier, target);
+      return identical(parent.identifier, target);
     }
     return false;
   }
 
   @override
   void visitChildren(AstVisitor visitor) {
     // There are no children to visit.
   }
 
   /**
@@ skipping 3701 matching lines @@
   }
 
   @override
   accept(AstVisitor visitor) => visitor.visitYieldStatement(this);
 
   @override
   void visitChildren(AstVisitor visitor) {
     _safelyVisitChild(_expression, visitor);
   }
 }