some small refactors
some small refactors

shengofsun/rDSN,glglwty/rDSN,pandaworrior/rDSN,shengofsun/rDSN,pandaworrior/rDSN,Microsoft/rDSN,qinzuoyan/rDSN,qinzuoyan/rDSN,linearregression/rDSN,pandaworrior/rDSN,lshmouse/rDSN,imzhenyu/rDSN,mkhoeini/rDSN,lshmouse/rDSN,glglwty/rDSN,ykwd/rDSN,qinzuoyan/rDSN,linearregression/rDSN,imzhenyu/rDSN,ykwd/rDSN,lshmouse/rDSN,mkhoeini/rDSN,shengofsun/rDSN,qinzuoyan/rDSN,imzhenyu/rDSN,goksyli/rDSN,pandaworrior/rDSN,mcfatealan/rDSN,Microsoft/rDSN,shengofsun/rDSN,goksyli/rDSN,shengofsun/rDSN,shengofsun/rDSN,linearregression/rDSN,imzhenyu/rDSN,Microsoft/rDSN,glglwty/rDSN,goksyli/rDSN,Microsoft/rDSN,mcfatealan/rDSN,lshmouse/rDSN,imzhenyu/rDSN,glglwty/rDSN,lshmouse/rDSN,ykwd/rDSN,lshmouse/rDSN,mcfatealan/rDSN,whiker/rDSN,linearregression/rDSN,ykwd/rDSN,whiker/rDSN,mcfatealan/rDSN,qinzuoyan/rDSN,whiker/rDSN,ykwd/rDSN,goksyli/rDSN,Microsoft/rDSN,shengofsun/rDSN,whiker/rDSN,whiker/rDSN,imzhenyu/rDSN,Microsoft/rDSN,qinzuoyan/rDSN,mkhoeini/rDSN,qinzuoyan/rDSN,imzhenyu/rDSN,mkhoeini/rDSN,lshmouse/rDSN,lshmouse/rDSN,pandaworrior/rDSN,imzhenyu/rDSN,shengofsun/rDSN,Microsoft/rDSN,Microsoft/rDSN,qinzuoyan/rDSN,glglwty/rDSN