Adding Properties / cryptic PROP_0
I find Adding Properties (https://gstreamer.freedesktop.org/documentation/plugin-development/basics/args.html?gi-language=c) extremely rudimentary and unhelpful. I've spent more time trying to figure out (unsuccessfully) why there's unused PROP_0 in the properties enum, which also presents in at least some Base GST elements (https://gitlab.freedesktop.org/gstreamer/gstreamer/-/blob/main/subprojects/gst-plugins-base/gst/audiotestsrc/gstaudiotestsrc.c#L117).
Neither Google nor chatGPT know anything about that, there's nothing in the docs, nothing in comments in the source code. Is it really required? Is property_id = 0 a reserved value?