Make analyzer more strong mode compliant

pkg/analyzer/lib/task/model.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.
 
 library analyzer.task.model;
 
 import 'dart:collection';
 import 'dart:developer';
 
 import 'package:analyzer/src/generated/engine.dart' hide AnalysisTask;
@@ skipping 167 matching lines @@
     if (inputs == null || !inputs.containsKey(name)) {
       return null;
     }
     return inputs[name];
   }
 
   /**
    * Return the value of the input with the given [name]. Throw an exception if
    * the input value is not defined.
    */
-  Object getRequiredInput(String name) {
+  Object/*=E*/ getRequiredInput/*<E>*/(String name) {
     if (inputs == null || !inputs.containsKey(name)) {
       throw new AnalysisException("Could not $description: missing $name");
     }
-    return inputs[name];
+    return inputs[name] as Object/*=E*/;
   }
 
   /**
    * Return the source associated with the target. Throw an exception if
    * the target is not associated with a source.
    */
   Source getRequiredSource() {
     Source source = target.source;
     if (source == null) {
       throw new AnalysisException("Could not $description: missing source");
@@ skipping 561 matching lines @@
   /**
    * A work should be done, but without any special urgency.
    */
   NORMAL,
 
   /**
    * Nothing to do.
    */
   NONE
 }