Wrote functions to convert collections and maps to strings and invoked

runtime/lib/byte_array.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.
 
 interface ByteArray extends List default _InternalByteArray {
   ByteArray(int length);
 
   int get length();
 
   int getInt8(int byteOffset);
@@ skipping 123 matching lines @@
 
   int removeLast() {
     throw const UnsupportedOperationException(
       "Cannot remove from a byte array");
   }
 
   int last() {
     return this[length - 1];
   }
 
+  String toString() {
+    return Collections.collectionToString(this);
+  }
+
   void setRange(int start, int length, List<int> from, [int startFrom = 0]) {
     if (length < 0) {
       throw new IllegalArgumentException("negative length $length");
     }
     if (from is ByteArray) {
       _setRange(start, length, from, startFrom);
     } else {
       Arrays.copy(from, startFrom, this, start, length);
     }
   }
@@ skipping 350 matching lines @@
 
   void _setFloat32(int byteOffset, double value)
     native "ExternalByteArray_setFloat32";
 
   double _getFloat64(int byteOffset)
     native "ExternalByteArray_getFloat64";
 
   void _setFloat64(int byteOffset, double value)
     native "ExternalByteArray_setFloat64";
 }