in cinder/volume/drivers/xenapi/lib.py (from grizzly version )
XenAPISession
|- ContextAwareSession
|- OpenStackXenAPISession
CompoundOperations
|- NFSOperationsMixIn
https://bitbucket.org/ncupdclab/sameved-cinder/src/2bc06f23ebfa63b95ca68bb0840df51c267208ce/volume/drivers/xenapi/lib.py?at=master
