add forgotten extern declaration
add forgotten extern declaration
ycaihua/skim-app,WoLpH/skim,ycaihua/skim-app,WoLpH/skim,WoLpH/skim,ycaihua/skim-app,ycaihua/skim-app,WoLpH/skim,WoLpH/skim,ycaihua/skim-app