It would be nice if IgnoreCheckPredicate in ignorePermissions in CommandHandler allowed for promises

Just thought it would be nice; I was able to integrate my database nicely for the prefix doing

prefix: async (msg: Message) => {

            var serverData = await client.db.getRepository(ServerSettings).findOne({
                guild: msg.guild.id
            });

            return serverData.prefix != null ? serverData.prefix : prefix
        }

But wasn't able to do the same for ignore permissions because it doesn't allow for promises.