Index: oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/MapRecord.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/MapRecord.java	(date 1491479067000)
+++ oak-segment-tar/src/main/java/org/apache/jackrabbit/oak/segment/MapRecord.java	(date 1497433956000)
@@ -304,8 +304,14 @@
             List<MapRecord> buckets = getBucketList(segment);
             List<Iterable<String>> keys =
                     newArrayListWithCapacity(buckets.size());
-            for (MapRecord bucket : buckets) {
-                keys.add(bucket.getKeys());
+            for (final MapRecord bucket : buckets) {
+                keys.add(new Iterable<String>() {
+                    @Nonnull
+                    @Override
+                    public Iterator<String> iterator() {
+                        return bucket.getKeys().iterator();
+                    }
+                });
             }
             return concat(keys);
         }