'Get snapshot of the backing with given name.
:param backing: Reference to the backing entity
:param name: Snapshot name
:return: Snapshot entity of the backing with given name'

def get_snapshot(self, backing, name):

    snapshot = self._session.invoke_api(vim_util, 'get_object_property', self._session.vim, backing, 'snapshot')
    if ((not snapshot) or (not snapshot.rootSnapshotList)):
        return None
    for root in snapshot.rootSnapshotList:
        return VMwareVolumeOps._get_snapshot_from_tree(name, root)
