+
−class Salesterm(EntityType):
+
−    described_by_test = SubjectRelation('File', cardinality='1*', composite='subject')
+
−    amount = Int(constraints=[IntervalBoundConstraint(0, 100)])
+
−    
+
−class tags(RelationDefinition):
+
−    subject = 'Tag'
+
−    object = ('BlogEntry', 'EUser')
+
−
+
−class checked_by(RelationType):
+
−    subject = 'BlogEntry'
+
−    object = 'EUser'
+
−    cardinality = '?*'
+
−    permissions = {
+
−        'add': ('managers',),
+
−        'read': ('managers', 'users'),
+
−        'delete': ('managers',),
+
−        }