gnome-keyring Secret.Collection.get_label()

[xor <gnome idlecore com>]

I've read the documentation for the get_label() method at:

https://lazka.github.io/pgi-docs/#Secret-1/classes/Collection.html#Secret.Collection.get_label

There is a note there mentioning that the label returned should be freed 
with GLib.free(). I tried that and I get the following error:

ValueError: Pointer arguments are restricted to integers, capsules, and 
None. See: https://bugzilla.gnome.org/show_bug.cgi?id=683599

I read the bug report, but I couldn't understand it. I considered the 
possibility that the documentation might be outdated, and the label 
doesn't required manual memory management anymore. I tried running this 
function a million times and see if the memory footprint of my program 
would increase. I noticed no increase. I'm still not sure though.

Could someone please clear this up for me?