update the tests to show a difference between `send(null)` and `send(undefiend)`
update the tests to show a difference between `send(null)` and `send(undefiend)`

chrisinajar/express,jymsy/express,BaggersIO/express,1amageek/express,Ivanwangcy/express,abdulhannanali/express,tyler-johnson/express,bjrmatos/express,stevemao/express,jenia0jenia/express,evilboss/express,nodejs-camp/booklog-ansaga,supasate/express,pathirana/express,nodejs-camp/booklog-chenyou,wesleytodd/express,corporateanon/express,KodkodGates/express,jinghuizhai/express,nodejs-camp/booklog-linkchen,vnglst/express,junxiong/express,RickyDan/express,flomotlik/express,mcanthony/express,auth0/express,blakeembrey/express,Lexine/express,sujianping/express,simplyianm/express,baldurh/express,neomadara/express,pstrike/express,awronka/express,hanqingnan/express,srichatala/express,danielrohers/express,fakedarren/express,yinhe007/express,btleffler/express,frootloops/express,ahdinosaur/express,cflynn07/express,XueQian/express,Lexine/express,ci-test2/express,dreamingblackcat/express,Eric-Vandenberg/express,1verson/express,hdngr/express,nodejs-camp/booklog-mora,hpcslag/express,gnowoel/express,buildsample/express,andriyl/express,kubrickology/express,nodejs-camp/booklog-tonebeta,nodejs-camp/booklog-ansaga,dieuly/express,xiaofuzi/express,robomc/express,Matrixbirds/express,Matrixbirds/express,sarvex/express,corporateanon/express,coreypnorris/express,weilixia/express,featurist/express,elkingtonmcb/express,lmtdit/express,TestingCI/express,juanpastas/express,expressjs/express,thepont/express,srichatala/express,stoskov/express,ci-test2/express,dotnetCarpenter/express,vidyar/express,danielrohers/express,swarajgiri/express,grigorkh/express,maraoz/express,featurist/express,dafabulousteach/express,jinghuizhai/express,pshomov/express,pshomov/express,soyuka/express,drzorm/express,mcanthony/express,svnh/express,stoskov/express,xiaofuzi/express,ZackBotkin/express,sibura/express,fuse-mars/express,adjohnson916/express,Haru1990/express,Riokai/express,gretac/express,btleffler/express,saisai/express,ericlu88/express,vidyar/express,chuym/express,kentcdodds/express,buildsample/express,maraoz/express,abhi3/express,nodejs-camp/booklog-archer,xtidt/express,JulyZhu/express,michaeljunlove/express,smcmurray/express,Ivanwangcy/express,mikewesthad/express,luxe-eng/valet-express.express,FernAbby/express,blakeembrey/express,samuelcastro/express,kentcdodds/express,pstrike/express,swstack/express,Eric-Vandenberg/express,nodejs-camp/booklog-ben,hpcslag/express,supasate/express,qitianchan/express,fakedarren/express,kunalpict/express,nbeydoon/express,kubrickology/express,za-creature/express,dgofman/express,xiaofuzi/express,benshiue/booklog-ben,grigorkh/express,Riokai/express,topaxi/express,weilixia/express,friederbluemle/express,jenia0jenia/express,chuym/express,za-creature/express,wtony/express,YR/express,Kevnz/express,LestaD/express,pathirana/express,YR/express,v10258/express,dgofman/express,benshiue/booklog-ben,devgeniem/express,mikewesthad/express,mauricionr/express,thepont/express,soyuka/express,nbeydoon/express,microlv/express,PeterWangPo/express,heicx/express,lmtdit/express,qitianchan/express,chrisinajar/express,Flip120/express,llwanghong/express,nodejs-camp/booklog-homa,coreypnorris/express,ralic/express,PUSEN/express,hightechweb/express,ralic/express,jinghuizhai/express,auth0/express,neomadara/express,methuz/express,blainsmith/express,evilboss/express,mimaidms/express,PeterWangPo/express,nodejs-camp/booklog-jason,caiocutrim/express,jenalgit/express,hightechweb/express,andrejewski/express,rgrove/express,demohi/express,leiqiang75/express,CrazySherman/express,evanlucas/express,Jonekee/express,za-creature/express,tianhengzhou/express,micha149/express,BaggersIO/express,dongseop/express,BaggersIO/express,sujianping/express,igarciaes/express,coreypnorris/express,XueQian/express,countdracular/express,listepo/express,vidyar/express,shanawarkhan/express,hanweifish/express,tianhengzhou/express,shanawarkhan/express,sarvex/express,gdeividas/express,devgeniem/express,gretac/express,dsupera13/express,ifraixedes/express,baldurh/express,igarciaes/express,kunalpict/express,Eric-Vandenberg/express,adjohnson916/express,r14r/fork_express_master,KodkodGates/express,HXYNODE/express,strongloop/express,HXYNODE/express,nodejs-camp/booklog-polo,yinhe007/express,nodejs-camp/booklog-polo,angelsanz/express,nodejs-camp/booklog-tonebeta-update,fuse-mars/express,sibura/express,caiocutrim/express,expressjs/express,demohi/express,VegeChou/express,Faiz7412/express,hpcslag/express,dsupera13/express,sarvex/express,youprofit/express,cflynn07/express,jenia0jenia/express,elkingtonmcb/express,hanweifish/express,stewartml/express,smcmurray/express,WangCao/express,1verson/express,wtony/express,nodejs-camp/booklog-s890506,vnglst/express,rupanjanbaidya/express,blairzhang/express,philxia/ex-tst-framework,kylezhang/express,XueQian/express,simudream/express,bjrmatos/express,stewartml/express,Riokai/express,hacksparrow/express,nodejs-camp/booklog-Zak,lmtdit/express,topaxi/express,nathan818fr/express,listepo/express,maraoz/express,philxia/ex-tst-framework,nodejs-camp/booklog-leo,stevemao/express,dotnetCarpenter/express,fineday32/express,dotnetCarpenter/express,RickyDan/express,r14r/fork_express_master,bercanozcan/express,simudream/express,udhayam/express,KodkodGates/express,simplyianm/express,qq645381995/express,frootloops/express,hanqingnan/express,michaeljunlove/express,tjmehta/express,friederbluemle/express,mimaidms/express,codeforgeek/express,junxiong/express,VegeChou/express,hdngr/express,1amageek/express,samuelcastro/express,nodejs-camp/booklog-jollen,saisai/express,JulyZhu/express,heicx/express,lian774739140/express,nodejs-camp/booklog-polo,lian774739140/express,microlv/express,tyler-johnson/express,robomc/express,ericlu88/express,kylezhang/express,ZackBotkin/express,nodejs-camp/booklog-leo,nodejs-camp/booklog-s890506,nodejs-camp/booklog-tonebeta-update,swstack/express,buildsample/express,leiqiang75/express,hl198181/express,r14r-work/fork_express_master,nodejs-camp/booklog-chle,CrazySherman/express,awronka/express,christopheranderson/express,vinodhalaharvi/express,stevemao/express,dongooo/express,listepo/express,michaeljunlove/express,methuz/express,codeforgeek/express,jimmykuo/express,mauricionr/express,llwanghong/express,nodejs-camp/booklog-mora,ifraixedes/express,nodejs-camp/booklog-ben,dongooo/express,aifeld/express,abdulhannanali/express,qq645381995/express,MoraLin/mora-test,wtony/express,Ju2ender/express,qitianchan/express,nodejs-camp/booklog-homa,jimmykuo/express,nbeydoon/express,evilboss/express,RanadeepPolavarapu/express,philxia/ex-tst-framework,rgrove/express,abhi3/express,chrisinajar/express,udhayam/express,andrejewski/express,jymsy/express,WangCao/express,jenalgit/express,flomotlik/express,gnowoel/express,luxe-eng/valet-express.express,lemelon/express,Faiz7412/express,juandav/express,hdngr/express,wesleytodd/express,nodejs-camp/booklog-chle,TestingCI/express,abhi3/express,swarajgiri/express,Talkyunyun/express,qq645381995/express,nodejs-camp/booklog-archer,grigorkh/express,tjmehta/express,vnglst/express,countdracular/express,nodejs-camp/booklog-tonebeta,stewartml/express,Flip120/express,dongseop/express,jenalgit/express,micha149/express,nodejs-camp/booklog-jason,bercanozcan/express,fineday32/express,smcmurray/express,rupanjanbaidya/express,nodejs-camp/booklog-ausir,WangCao/express,supasate/express,strongloop/express,svnh/express,simudream/express,Ju2ender/express,WebStyle/express,swarajgiri/express,Ju2ender/express,nodejs-camp/booklog-jollen,bercanozcan/express,dafabulousteach/express,christopheranderson/express,gdeividas/express,angelsanz/express,stoskov/express,fanzetao/express,nodejs-camp/booklog-ausir,nathan818fr/express,friederbluemle/express,juanpastas/express,kylezhang/express,dafabulousteach/express,hl198181/express,v10258/express,svnh/express,PUSEN/express,LestaD/express,ci-test2/express,r14r-work/fork_express_master,youprofit/express,v10258/express,Haru1990/express,Kevnz/express,ZackBotkin/express,TestingCI/express,corporateanon/express,blakeembrey/express,abdulhannanali/express,kunalpict/express,RanadeepPolavarapu/express,emvici/emvici-reqres-tify,lemelon/express,philxia/ex-tst-framework,gnowoel/express,junxiong/express,dieuly/express,featurist/express,angelsanz/express,1amageek/express,evanlucas/express,topaxi/express,youprofit/express,blairzhang/express,fakedarren/express,andriyl/express,dongseop/express,fanzetao/express,drzorm/express,Talkyunyun/express,nodejs-camp/booklog-Zak,vinodhalaharvi/express,juandav/express,dreamingblackcat/express,nodejs-camp/booklog-chenyou,ahdinosaur/express,Jonekee/express,devgeniem/express,luxe-eng/valet-express.express,LestaD/express,hacksparrow/express,FernAbby/express,nodejs-camp/booklog-linkchen,MoraLin/mora-test,Flip120/express,blairzhang/express,aifeld/express,dreamingblackcat/express,blainsmith/express,WebStyle/express,Faiz7412/express,vinodhalaharvi/express,xtidt/express