Fix generics in IteratorChain.IteratorChain(Collection)

src/changes/changes.xml

@@ -38,6 +38,7 @@
     <action type="fix" dev="ggregory" due-to="Gary Gregory, Alex Herbert">BloomFilterExtractor.flatten() should throw an exception instead of returning null.</action>
     <action type="fix" dev="ggregory" due-to="Gary Gregory, Claude Warren">Improve WrappedBloomFilterTest. All tests now assert copy() the same way.</action>
     <action type="fix" dev="ggregory" due-to="Gary Gregory,  Daniele" issue="COLLECTIONS-860">Javadoc CollectionBag.add* to throw ClassCastException.</action>
+    <action type="fix" dev="ggregory" due-to="Gary Gregory">Fix generics in IteratorChain.IteratorChain(Collection).</action>
     <!-- ADD -->
     <action type="add" dev="ggregory" due-to="Gary Gregory">LayerManager.Builder implements Supplier.</action>
     <action type="add" dev="ggregory" due-to="Gary Gregory, hemanth0525">Add CollectionUtils.duplicateList(Collection).</action>

src/main/java/org/apache/commons/collections4/iterators/IteratorChain.java

@@ -97,7 +97,7 @@ public class IteratorChain<E> implements Iterator<E> {
      * @throws ClassCastException if iterators collection doesn't contain an
      * iterator
      */
-    public IteratorChain(final Collection<Iterator<? extends E>> iteratorChain) {
+    public IteratorChain(final Collection<? extends Iterator<? extends E>> iteratorChain) {
         for (final Iterator<? extends E> iterator : iteratorChain) {
             addIterator(iterator);
         }

src/test/java/org/apache/commons/collections4/iterators/IteratorChainTest.java

@@ -137,6 +137,21 @@ public class IteratorChainTest extends AbstractIteratorTest<String> {
         }
     }
 
+    @Test
+    public void testConstructList() {
+        final List<Iterator<String>> list = new ArrayList<>();
+        list.add(list1.iterator());
+        list.add(list2.iterator());
+        list.add(list3.iterator());
+        final List<String> expected = new ArrayList<>(list1);
+        expected.addAll(list2);
+        expected.addAll(list3);
+        final IteratorChain<String> iter = new IteratorChain<>(list);
+        final List<String> actual = new ArrayList<>();
+        iter.forEachRemaining(actual::add);
+        assertEquals(actual, expected);
+    }
+
     @Test
     @Override
     public void testRemove() {