Define metaclass at class level

product.py

@@ -3,21 +3,19 @@
 from trytond.model import ModelView, ModelSQL, fields
 from trytond.pool import PoolMeta
 
-__all__ = ['Brand', 'Template']
-__metaclass__ = PoolMeta
-
 from trytond.modules.product.product import STATES, DEPENDS
 
+__all__ = ['Brand', 'Template']
+
 
 class Brand(ModelSQL, ModelView):
     '''Brand'''
     __name__ = 'product.brand'
-
     name = fields.Char('Name', required=True)
 
 
 class Template:
     __name__ = 'product.template'
-
+    __metaclass__ = PoolMeta
     brand = fields.Many2One('product.brand', 'Brand', states=STATES,
         depends=DEPENDS)