--- a/src/pyams_security/interfaces/__init__.py	Wed Jun 07 10:07:10 2017 +0200
+++ b/src/pyams_security/interfaces/__init__.py	Wed Jul 12 12:32:29 2017 +0200
@@ -610,6 +610,9 @@
                                     value_type=TextLine(),
                                     default=())
 
+    def effective_principals(self, principal_id, request=None, context=None):
+        """Get effective principals of given principal for context"""
+
     def get_plugin(self, name):
         """Get plug-in matching given name"""