[erlang-questions] -extends(Module)

[Ulf Wiger]

I noticed that epp.erl recognizes an -extends(M) attribute,
and uses this to define a macro, BASE_MODULE (and
corresponding BASE_MODULE_STRING).

This seems interesting, but I can't find any other references
to it, either in documentation or in code.

Is it work in progress or remnants of a discarded experiment?

BR,
Ulf W