id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
28167	cache backend's SessionStore.exists() returns None if session_key is None	Tim Graham	Tim Graham	`exists()` should always return True or False.	Bug	closed	contrib.sessions	1.11	Normal	fixed			Accepted	1	0	0	0	0	0