stdlib: Fixing erroneous typing in Simulator __init__

The key in the `on_exit_event` dictionary can only be an ExitEvent. The
typing information here suggested a string could be passed. This is not
the case. This patch fixes the issue.

Change-Id: Iaa4b66417c15e31f6aafe9e550a7552461a15be1
Maintainer: Bobby Bruce <>
Tested-by: kokoro <>
Reviewed-by: Bobby Bruce <>
1 file changed