Fix analyzer warning / bug: Iterable was treated as if it has sublist()

lib/src/protobuf/pb_list.dart

 // Copyright (c) 2011, 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 protobuf;
 
 class PbList<E> extends Object with ListMixin<E> implements List<E> {
 
   PbList() : _wrappedList = <E>[];
 
@@ skipping 70 matching lines @@
     _wrappedList.addAll(collection);
   }
 
   /**
    * Copies [:end - start:] elements of the [from] array, starting
    * from [skipCount], into [:this:], starting at [start].
    * Throws an [UnsupportedError] if the list is
    * not extendable.
    */
   void setRange(int start, int end, Iterable<E> from, [int skipCount = 0]) {
-    from.sublist(skipCount, skipCount + end - start).forEach(_validate);
+    // NOTE: In case `take()` returns less than `end - start` elements, the
+    // _wrappedList will fail with a `StateError`.
+    from.skip(skipCount).take(end - start).forEach(_validate);
     _wrappedList.setRange(start, end, from, skipCount);
   }
 
   /**
    * Inserts a new element in the list.
    * The element must be valid (and not nullable) for the PbList type.
    */
   void insert(int index, E element) {
     _validate(element);
     _wrappedList.insert(index, element);
@@ skipping 98 matching lines @@
  * [:-3.4E38, 3.4E38:], i.e., with the IEEE single-precision range.
  */
 class PbFloatList extends PbList<double> {
   void _validateElement(double val) {
     if (!_isFloat32(val)) {
       throw new ArgumentError('Illegal to add value (${val}):'
           ' out of range for float');
     }
   }
 }