Writing HK2 components in GlassFish 4

In version 3 there is this guide on how to write components(including HK2 components):
Oracle GlassFish Server 3.0.1 Add-On Component Development Guide

This documentation is not available with GF4. Why not?

Why am I asking?

Because I want to write a custom Logging Handler, as documented in Chapter 7 of the administration guide(https://glassfish.java.net/docs/4.0/administration-guide.pdf).

"Note: The custom handler class should be packaged in an OSGi
module and the JAR file placed in the as-install/modules directory."

So how exactly do I proceed to create a HK2 component for GF4? Is it the same as GF3?

Thanks, Roland