--- a/entities/adapters.py	Tue Sep 22 15:24:58 2015 +0200
+++ b/entities/adapters.py	Tue Sep 22 15:31:44 2015 +0200
@@ -187,7 +187,7 @@
         raise NotImplementedError
 
     def download_data(self):
-        """return actual data of the downloadable content"""
+        """return actual data (bytes) of the downloadable content"""
         raise NotImplementedError
 
 # XXX should propose to use two different relations for children/parent