Config.lock() return exception when normalize is on

[jnpr-raylam]

dev=Device('172.27.62.164',user='root',passwd='lab123',normalize=True)
dev.open()
Device(172.27.62.164)
cu=Config(dev)
cu.lock()
Traceback (most recent call last):
File "", line 1, in
File "/root/pyez2.0/lib/python2.7/site-packages/jnpr/junos/utils/config.py", line 467, in lock
raise LockError(rsp=JXML.remove_namespaces(err.xml))
AttributeError: 'exceptions.AttributeError' object has no attribute 'xml'

If normalize is not enabled, no problem
This problem is introduced in pyez 2.0