ReadiumReaderWidget's loadingWidget does nothing

[AndreasLymalmMTM]

Description

ReadiumReaderWidget has the parameter

loadingWidget = const Center(child: CircularProgressIndicator())

However, this is never used anywhere inside the widget (no matter using the dafult one or passing a custom one loading widget).

Expected Behaviour

Is loadingWidget supposed to fill the whole ReadiumReaderWidget on initial load? If not, how should it be used?