Index: oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/tree/TreeFactory.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/tree/TreeFactory.java	(date 1421313559000)
+++ oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/tree/TreeFactory.java	(date 1421253486000)
@@ -19,6 +19,7 @@
 import javax.annotation.Nonnull;
 
 import org.apache.jackrabbit.oak.api.Tree;
+import org.apache.jackrabbit.oak.plugins.tree.impl.AbstractTree;
 import org.apache.jackrabbit.oak.plugins.tree.impl.ImmutableTree;
 import org.apache.jackrabbit.oak.plugins.tree.impl.NodeBuilderTree;
 import org.apache.jackrabbit.oak.spi.state.NodeBuilder;
@@ -39,4 +40,14 @@
     public static Tree createReadOnlyTree(@Nonnull NodeState rootState) {
         return new ImmutableTree(rootState);
     }
+
+    public static NodeState createNodeState(@Nonnull Tree tree) {
+        if (tree instanceof AbstractTree) {
+            return ((AbstractTree) tree).getNodeState();
+        } else {
+            throw new UnsupportedOperationException(
+                    "Cannot create a node state from tree of type " + tree.getClass());
+        }
+    }
+
 }
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