no need to remove observer from notification center
no need to remove observer from notification center
ycaihua/skim-app,WoLpH/skim,WoLpH/skim,ycaihua/skim-app,ycaihua/skim-app,ycaihua/skim-app,ycaihua/skim-app,WoLpH/skim,WoLpH/skim,WoLpH/skim