Handle an empty class addition or removal.  Closes #34.
Handle an empty class addition or removal.  Closes #34.

chrismoulton/tether,ktardthong/tether,SRobertZ/tether,martijnrusschen/tether,StileEducation/tether,xLegoz/tether,darobin/tether,xLegoz/tether,dieface/tether,dandv/tether,pzuraq/tether,lneir/tether,martijnrusschen/tether,SRobertZ/tether,dandv/tether,varblob/tether,HubSpot/tether,mcanthony/tether