'Retrieve libvirt guest object for an instance.
All libvirt error handling should be handled in this method and
relevant nova exceptions should be raised in response.
:param instance: a nova.objects.Instance object
:returns: a nova.virt.libvirt.Guest object
:raises exception.InstanceNotFound: The domain was not found
:raises exception.InternalError: A libvirt error occurred'

def get_guest(self, instance):

    return libvirt_guest.Guest(self.get_domain(instance))
