def get_qos_policy_group_name(volume):
 if ('id' in volume):
  return (OPENSTACK_PREFIX + volume['id'])
 return None

def get_qos_policy_group_name ( volume ) : if ( 'id' in volume ) : return ( OPENSTACK_PREFIX + volume [ 'id' ] ) return None
return the name of backend qos policy group based on its volume id .