Split the JSON output into multiple lines.

pkg/analyzer/lib/src/generated/error.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 analyzer.src.generated.error;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart' show AstNode;
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 2204 matching lines @@
    */
   static const CompileTimeErrorCode REFERENCED_BEFORE_DECLARATION =
       const CompileTimeErrorCode('REFERENCED_BEFORE_DECLARATION',
           "Local variables cannot be referenced before they are declared");
 
   /**
    * 12.8.1 Rethrow: It is a compile-time error if an expression of the form
    * <i>rethrow;</i> is not enclosed within a on-catch clause.
    */
   static const CompileTimeErrorCode RETHROW_OUTSIDE_CATCH =
-      const CompileTimeErrorCode(
-          'RETHROW_OUTSIDE_CATCH', "rethrow must be inside of a catch clause");
+      shared_messages.RETHROW_OUTSIDE_CATCH;
 
   /**
    * 13.12 Return: It is a compile-time error if a return statement of the form
    * <i>return e;</i> appears in a generative constructor.
    */
   static const CompileTimeErrorCode RETURN_IN_GENERATIVE_CONSTRUCTOR =
       shared_messages.RETURN_IN_GENERATIVE_CONSTRUCTOR;
 
   /**
    * 13.12 Return: It is a compile-time error if a return statement of the form
@@ skipping 3454 matching lines @@
    * Initialize a newly created error code to have the given [name].
    */
   const TodoCode(String name) : super(name, "{0}");
 
   @override
   ErrorSeverity get errorSeverity => ErrorSeverity.INFO;
 
   @override
   ErrorType get type => ErrorType.TODO;
 }