Remove duplicated stack trace from error notifications

pkg/analyzer/lib/src/generated/java_engine.dart

 library java.engine;
 
 import 'interner.dart';
 import 'java_core.dart';
 
 /**
  * A predicate is a one-argument function that returns a boolean value.
  */
 typedef bool Predicate<E>(E argument);
 
@@ skipping 79 matching lines @@
       if (stackTrace != null) {
         buffer.writeln(stackTrace.toString());
       }
       CaughtException cause = analysisException.cause;
       if (cause != null) {
         buffer.write('Caused by ');
         cause._writeOn(buffer);
       }
     } else {
       buffer.writeln(exception.toString());
-      buffer.writeln(stackTrace.toString());
+      if (stackTrace != null) {
+        buffer.writeln(stackTrace.toString());
+      }
     }
   }
 }
 
 class FileNameUtilities {
   static String getExtension(String fileName) {
     if (fileName == null) {
       return "";
     }
     int index = fileName.lastIndexOf('.');
@@ skipping 252 matching lines @@
   }
 }
 
 class UUID {
   static int __nextId = 0;
   final String id;
   UUID(this.id);
   String toString() => id;
   static UUID randomUUID() => new UUID((__nextId).toString());
 }