id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
136	Transformer.filter returns inconsistently marked stream	Dave Abrahams <dave@…>	athomas	The resulting stream ends up with a mixture of marked and unmarked events.  Because the current tests just use `print` on the stream, the error is hidden.  You can see the problem by doing `print(list( resultstream ))`.  You need to decide whether the result is supposed to be a marked or an unmarked stream.  I suggest changing all filtering doctests by appending a new filter that asserts the correctness of the stream format before passing it through to the output, or updating Stream.render() to do the invariant check. 	defect	closed	major	0.5	General	0.4.2	fixed