gtanner/callback-js — comment on commit e5f3920aa79473fd93263458a0c6603f5790cd80
File:  line 0
By gtanner:

Idea would be:

event.trigger("foo");
event.on("foo", func);
event.once(["foo", "bar", "baz"], func);
event.once("foo", func);

That way we are not required to "create" an event to be able to register for it.