Make ref_counts be a defaultdict instance
Make ref_counts be a defaultdict instance

chrishokamp/fuel,rodrigob/fuel,capybaralet/fuel,dribnet/fuel,ejls/fuel,harmdevries89/fuel,vdumoulin/fuel,glewis17/fuel,dwf/fuel,capybaralet/fuel,jbornschein/fuel,vdumoulin/fuel,rizar/fuel,mjwillson/fuel,mila-udem/fuel,laurent-dinh/fuel,EderSantana/fuel,dmitriy-serdyuk/fuel,EderSantana/fuel,bouthilx/fuel,dwf/fuel,harmdevries89/fuel,janchorowski/fuel,chrishokamp/fuel,orhanf/fuel,lamblin/fuel,udibr/fuel,bouthilx/fuel,janchorowski/fuel,jbornschein/fuel,dhruvparamhans/fuel,codeaudit/fuel,glewis17/fuel,markusnagel/fuel,udibr/fuel,aalmah/fuel,dhruvparamhans/fuel,dribnet/fuel,aalmah/fuel,rizar/fuel,markusnagel/fuel,mila-udem/fuel,hantek/fuel,ejls/fuel,rodrigob/fuel,mjwillson/fuel,hantek/fuel,dmitriy-serdyuk/fuel,lamblin/fuel,codeaudit/fuel,orhanf/fuel,laurent-dinh/fuel