Revert "change class join event"

This reverts commit 1c816ceb7ea01f5939c899cf2a93fbc967c34554.
Revert "change join event file"

This reverts commit 07c8e2109420eac6403c91940155b02b553fee4c.
Revert "revert the code"

This reverts commit 22d14d8b37a08cdad426ecf242c48b5cf501db19.
Revert "no message"

This reverts commit f8142f328c93e0b4e8a64a5e020c98d67c0911bd.