Alchemy.Events.on_user_unban

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

on_user_unban(func)

(macro)

Registers a handle triggering whenever a user gets unbanned from a guild.

args : Alchemy.User.t, snowflake Recieves the user struct, as well as the id of the guild from which the user has been unbanned.

Examples

Events.on_user_unban(:reban)
def reban(user, guild) do
  Client.ban_member(guild_id, user.id)
end