From d36f6924e6b8ecf4a7b9ba989456783baf019666 Mon Sep 17 00:00:00 2001
From: Stan Lagun <slagun@mirantis.com>
Date: Wed, 10 Feb 2016 19:01:15 +0300
Subject: [PATCH] Adds abc.ABCMeta for base smart-type classes

Base classes that shouldn't be instantiated directly
should be marked as abstract

Change-Id: Ie26e20f3c60e5e6beab3d093e82ae29195ce4d95
---
 yaql/language/yaqltypes.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/yaql/language/yaqltypes.py b/yaql/language/yaqltypes.py
index 48c3968..0f77639 100644
--- a/yaql/language/yaqltypes.py
+++ b/yaql/language/yaqltypes.py
@@ -25,16 +25,19 @@ from yaql.language import utils
 from yaql import yaql_interface
 
 
+@six.add_metaclass(abc.ABCMeta)
 class HiddenParameterType(object):
     # noinspection PyMethodMayBeStatic,PyUnusedLocal
     def check(self, value, context, engine, *args, **kwargs):
         return True
 
 
+@six.add_metaclass(abc.ABCMeta)
 class LazyParameterType(object):
     pass
 
 
+@six.add_metaclass(abc.ABCMeta)
 class SmartType(object):
     def __init__(self, nullable):
         self.nullable = nullable