Wrote functions to convert collections and maps to strings and invoked

runtime/lib/growable_array.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
 class GrowableObjectArray<T> implements List<T> {
   ObjectArray<T> backingArray;
 
   factory GrowableObjectArray._uninstantiable() {
     throw const UnsupportedOperationException(
         "GrowableObjectArray can only be allocated by the VM");
   }
@@ skipping 208 matching lines @@
 
   void clear() {
     this.length = 0;
   }
 
   void sort(int compare(T a, T b)) {
     DualPivotQuicksort.sort(this, compare);
   }
 
   String toString() {
-    return Arrays.asString(this);
+    return Collections.collectionToString(this);
   }
 
   Iterator<T> iterator() {
     return new VariableSizeArrayIterator<T>(this);
   }
 }
 
 
 // Iterator for arrays with variable size.
 class VariableSizeArrayIterator<T> implements Iterator<T> {
   VariableSizeArrayIterator(GrowableObjectArray<T> array)
       : _array = array,  _pos = 0 {
   }
 
   bool hasNext() {
     return _array._length > _pos;
   }
 
   T next() {
     if (!hasNext()) {
       throw const NoMoreElementsException();
     }
     return _array[_pos++];
   }
 
   final GrowableObjectArray<T> _array;
   int _pos;
 }