+ if hasattr(iter_cls, '_user_can_seek_ns_from_origin') and not hasattr(
+ iter_cls, '_user_seek_ns_from_origin'
+ ):
+ raise bt2._IncompleteUserClass(
+ "cannot create component class '{}': message iterator class implements _user_can_seek_ns_from_origin but not _user_seek_ns_from_origin".format(
+ cls.__name__
+ )
+ )
+
+ if hasattr(iter_cls, '_user_can_seek_beginning') and not hasattr(
+ iter_cls, '_user_seek_beginning'
+ ):
+ raise bt2._IncompleteUserClass(
+ "cannot create component class '{}': message iterator class implements _user_can_seek_beginning but not _user_seek_beginning".format(
+ cls.__name__
+ )
+ )
+