First check in for pub package manager.

utils/pub/utils.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.
+
+/**
+ * Generic utility functions. Stuff that should possibly be in core.
+ */
+#library('pub_utils');
+
+// TODO(rnystrom): Move into String?
+/** Pads [source] to [length] by adding spaces at the end. */
+String padRight(String source, int length) {
+  final result = new StringBuffer();
+  result.add(source);
+
+  while (result.length < length) {
+    result.add(' ');
+  }
+
+  return result.toString();
+}