Add List.insert.

sdk/lib/_collection_dev/list.dart

 // Copyright (c) 2013, 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.
 
 part of dart._collection.dev;
 
 /**
  * Class implementing the read-operations on [List].
  *
  * Implements all read-only operations, except [:operator[]:] and [:length:],
@@ skipping 43 matching lines @@
   void add(E value) {
     throw new UnsupportedError(
         "Cannot add to a fixed-length list");
   }
 
   void addLast(E value) {
     throw new UnsupportedError(
         "Cannot add to a fixed-length list");
   }
 
+  void insertAt(int index, E value) {
+    throw new UnsupportedError(
+        "Cannot add to a fixed-length list");
+  }
+
   void addAll(Iterable<E> iterable) {
     throw new UnsupportedError(
         "Cannot add to a fixed-length list");
   }
 
   void remove(E element) {
     throw new UnsupportedError(
         "Cannot remove from a fixed-length list");
   }
 
@@ skipping 56 matching lines @@
   void add(E value) {
     throw new UnsupportedError(
         "Cannot add to an unmodifiable list");
   }
 
   void addLast(E value) {
     throw new UnsupportedError(
         "Cannot add to an unmodifiable list");
   }
 
+  E insertAt(int index, E value) {
+    throw new UnsupportedError(
+        "Cannot add to an unmodifiable list");
+  }
+
   void addAll(Iterable<E> iterable) {
     throw new UnsupportedError(
         "Cannot add to an unmodifiable list");
   }
 
   void remove(E element) {
     throw new UnsupportedError(
         "Cannot remove from an unmodifiable list");
   }
 
@@ skipping 87 matching lines @@
  */
 class CodeUnits extends UnmodifiableListBase<int> {
   /** The string that this is the code units of. */
   String _string;
 
   CodeUnits(this._string);
 
   int get length => _string.length;
   int operator[](int i) => _string.codeUnitAt(i);
 }