Alchemy.Events.on_reaction_remove_all

You're seeing just the macro on_reaction_remove_all, go back to Alchemy.Events module for more information.
Link to this macro

on_reaction_remove_all(func)

(macro)

Registere a handle triggering whenever a user deletes all reactions to a message.

args : snowflake, snowflake

Receives the channel_id and message_id