Remove deprecated APIs.

lib/src/utils.dart

 // Copyright (c) 2015, 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.
 
 import 'package:source_span/source_span.dart';
 
 /// Runs [body] and wraps any format exceptions it produces.
 ///
 /// [name] should describe the type of thing being parsed, and [value] should be
 /// its actual value.
-wrapFormatException(String name, String value, body()) {
+/*=T*/ wrapFormatException/*<T>*/(String name, String value, /*=T*/ body()) {
   try {
     return body();
   } on SourceSpanFormatException catch (error) {
     throw new SourceSpanFormatException(
         'Invalid $name: ${error.message}', error.span, error.source);
   } on FormatException catch (error) {
     throw new FormatException(
         'Invalid $name "$value": ${error.message}',
         error.source,
         error.offset);
   }
 }