INodeDirectory dir3 = fsdir.getINode4Write(sdir3.toString()).asDirectory();
INodeDirectory mockDir3 = spy(dir3);
// fail the rename but succeed in undo
doReturn(false).when(mockDir3).addChild((INode) Mockito.isNull(),
anyBoolean(), (Snapshot) anyObject(), (INodeMap) anyObject());
Mockito.when(mockDir3.addChild((INode) Mockito.isNotNull(),
anyBoolean(), (Snapshot) anyObject(),
(INodeMap) anyObject())).thenReturn(false).thenCallRealMethod();
INodeDirectory root = fsdir.getINode4Write("/").asDirectory();
root.replaceChild(dir3, mockDir3, fsdir.getINodeMap());
foo3Node.setParent(mockDir3);