Require two type arguments for map literals (issue 4522).

pkg/logging/logging.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Provides APIs for debugging and error logging. This library introduces
  * abstractions similar to those used in other languages, such as the Closure JS
  * Logger and java.util.logging.Logger.
  */
 #library('logging');
@@ skipping 36 matching lines @@
   List<LoggerHandler> _handlers;
 
   /**
    * Singleton constructor. Calling `new Logger(name)` will return the same
    * actual instance whenever it is called with the same string name.
    */
   factory Logger(String name) {
     if (name.startsWith('.')) {
       throw new IllegalArgumentException("name shouldn't start with a '.'");
     }
-    if (_loggers == null) _loggers = <Logger>{};
+    if (_loggers == null) _loggers = <String, Logger>{};
     if (_loggers.containsKey(name)) return _loggers[name];
 
     // Split hierarchical names (separated with '.').
     int dot = name.lastIndexOf('.');
     Logger parent = null;
     String thisName;
     if (dot == -1) {
       if (name != '') parent = new Logger('');
       thisName = name;
     } else {
@@ skipping 257 matching lines @@
 
   /** Associated exception message (if any) when recording errors messages. */
   String exceptionText;
 
   LogRecord(
       this.level, this.message, this.loggerName,
       [time, this.exception, this.exceptionText]) :
     this.time = (time == null) ? new Date.now() : time,
     this.sequenceNumber = LogRecord._nextNumber++;
 }