From cd218dc12db048850af040fea1e259844cc9318c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C5=82a=C5=BCej=20Osi=C5=84ski?=
 <804945+blazejosinski@users.noreply.github.com>
Date: Thu, 10 Aug 2023 00:12:42 +0200
Subject: [PATCH] Add assert description. (#894)

**The assert was missing a description, I fixed it.**

Please note: there is an error in the documentations, but it does not
seem to be related to my changes.
---
 tianshou/env/venvs.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tianshou/env/venvs.py b/tianshou/env/venvs.py
index 09b2090..e2477d4 100644
--- a/tianshou/env/venvs.py
+++ b/tianshou/env/venvs.py
@@ -280,7 +280,7 @@ class BaseVectorEnv(object):
         assert (
             isinstance(ret_list[0], (tuple, list)) and len(ret_list[0]) == 2
             and isinstance(ret_list[0][1], dict)
-        )
+        ), "The environment does not adhere to the Gymnasium's API."
 
         obs_list = [r[0] for r in ret_list]