[schema] import _ from cubicweb

schema.py

@@ -3,8 +3,11 @@ from yams.buildobjs import (EntityType, SubjectRelation, String, RichString,
 from yams.reader import context
 from cubicweb.schema import RRQLExpression, RQLConstraint
 
+try:
+    from cubicweb import _
+except ImportError:
+    _ = unicode
 
-_ = unicode
 
 class Person(EntityType):
     """a physical person"""
@@ -24,7 +27,6 @@ class Person(EntityType):
         im_address = SubjectRelation('IMAddress', composite='subject')
 
 
-
 class use_email(RelationDefinition):
     """person's email account"""
     __permissions__ = {
@@ -49,4 +51,3 @@ class primary_email(RelationDefinition):
     object = "EmailAddress"
     cardinality = '??'
     constraints= [RQLConstraint('S use_email O')]
-