Support for XEP-0105 Extended Capabilities ?

[picaoao]

I would like to use a Personal Eventing Protocol feature of generating notifications based on presence. Correct if I'm wrong, but what I understood from reading the XEPs is that in order to do so, a client (entity) has to announce presence with extended capabilities and with that announce the features it is interested, so that the pubsub (pep) service of an entity can automatically publish the messages to the subscribed (presence) entities.
I would be great to have library support to generate a iq disco result stanzas with identities, features, forms, and also be able to generate a hash out of that to include it in the presence stanzas.

I looked at processone library and they seem to support it:
https://github.com/processone/exmpp/blob/master/src/core/exmpp_caps.erl