I believe this is already the behaviour of loading... because there will never be a list filter while loading... is that not correct?
See comments below... and refer to documentation in the top of this file which explains this for the event... I suspect this is also the case for the `histogram` method.

If not, could this not be done in a more elegant way by callling `_clearFilterList` in `histogramfilter_state` which might do the trick... if I'm not mistaken. Not sure it this could create other problems... but if so, then I'm not sure I see them..