ParamSpec.sink

The initial reference count of a newly created #GParamSpec is 1, even though no one has explicitly called [gobject.param_spec.ParamSpec.ref_] on it yet. So the initial reference count is flagged as "floating", until someone calls g_param_spec_ref (pspec); g_param_spec_sink (pspec); in sequence on it, taking over the initial reference count (thus ending up with a pspec that has a reference count of 1 still, but is not flagged "floating" anymore).