Replace do_add_subscription() in test_narrow.
Replace do_add_subscription() in test_narrow.

j831/zulip,dattatreya303/zulip,showell/zulip,aakash-cr7/zulip,souravbadami/zulip,rht/zulip,AZtheAsian/zulip,jackrzhang/zulip,Jianchun1/zulip,jrowan/zulip,peguin40/zulip,jrowan/zulip,PhilSk/zulip,peguin40/zulip,JPJPJPOPOP/zulip,aakash-cr7/zulip,andersk/zulip,arpith/zulip,showell/zulip,eeshangarg/zulip,cosmicAsymmetry/zulip,isht3/zulip,Jianchun1/zulip,calvinleenyc/zulip,kou/zulip,showell/zulip,christi3k/zulip,Juanvulcano/zulip,mahim97/zulip,christi3k/zulip,ryanbackman/zulip,j831/zulip,kou/zulip,vaidap/zulip,verma-varsha/zulip,calvinleenyc/zulip,samatdav/zulip,dattatreya303/zulip,brockwhittaker/zulip,vikas-parashar/zulip,jphilipsen05/zulip,reyha/zulip,rht/zulip,PhilSk/zulip,christi3k/zulip,blaze225/zulip,verma-varsha/zulip,sharmaeklavya2/zulip,Juanvulcano/zulip,souravbadami/zulip,Galexrt/zulip,verma-varsha/zulip,TigorC/zulip,grave-w-grave/zulip,jackrzhang/zulip,j831/zulip,synicalsyntax/zulip,samatdav/zulip,blaze225/zulip,vabs22/zulip,sharmaeklavya2/zulip,sonali0901/zulip,blaze225/zulip,eeshangarg/zulip,tommyip/zulip,sonali0901/zulip,jrowan/zulip,ryanbackman/zulip,KingxBanana/zulip,Diptanshu8/zulip,timabbott/zulip,jainayush975/zulip,Diptanshu8/zulip,j831/zulip,jainayush975/zulip,sonali0901/zulip,kou/zulip,jainayush975/zulip,niftynei/zulip,grave-w-grave/zulip,paxapy/zulip,TigorC/zulip,susansls/zulip,vabs22/zulip,TigorC/zulip,KingxBanana/zulip,Jianchun1/zulip,amanharitsh123/zulip,dattatreya303/zulip,amanharitsh123/zulip,niftynei/zulip,niftynei/zulip,hackerkid/zulip,SmartPeople/zulip,SmartPeople/zulip,amanharitsh123/zulip,zulip/zulip,JPJPJPOPOP/zulip,amanharitsh123/zulip,arpith/zulip,PhilSk/zulip,jackrzhang/zulip,SmartPeople/zulip,brockwhittaker/zulip,hackerkid/zulip,kou/zulip,shubhamdhama/zulip,sonali0901/zulip,brockwhittaker/zulip,rht/zulip,susansls/zulip,synicalsyntax/zulip,jrowan/zulip,brockwhittaker/zulip,SmartPeople/zulip,amyliu345/zulip,rishig/zulip,punchagan/zulip,rht/zulip,shubhamdhama/zulip,JPJPJPOPOP/zulip,eeshangarg/zulip,dhcrzf/zulip,cosmicAsymmetry/zulip,PhilSk/zulip,vaidap/zulip,TigorC/zulip,samatdav/zulip,eeshangarg/zulip,TigorC/zulip,vikas-parashar/zulip,synicalsyntax/zulip,jphilipsen05/zulip,vaidap/zulip,christi3k/zulip,Galexrt/zulip,grave-w-grave/zulip,vikas-parashar/zulip,vikas-parashar/zulip,vabs22/zulip,brainwane/zulip,eeshangarg/zulip,zulip/zulip,dawran6/zulip,synicalsyntax/zulip,rishig/zulip,aakash-cr7/zulip,grave-w-grave/zulip,zacps/zulip,andersk/zulip,timabbott/zulip,Galexrt/zulip,cosmicAsymmetry/zulip,verma-varsha/zulip,dhcrzf/zulip,calvinleenyc/zulip,dattatreya303/zulip,andersk/zulip,brockwhittaker/zulip,jrowan/zulip,brainwane/zulip,Juanvulcano/zulip,shubhamdhama/zulip,isht3/zulip,paxapy/zulip,j831/zulip,peguin40/zulip,rht/zulip,Diptanshu8/zulip,hackerkid/zulip,susansls/zulip,eeshangarg/zulip,isht3/zulip,reyha/zulip,amyliu345/zulip,tommyip/zulip,calvinleenyc/zulip,zulip/zulip,paxapy/zulip,souravbadami/zulip,punchagan/zulip,joyhchen/zulip,timabbott/zulip,susansls/zulip,AZtheAsian/zulip,JPJPJPOPOP/zulip,joyhchen/zulip,dhcrzf/zulip,christi3k/zulip,paxapy/zulip,jainayush975/zulip,rishig/zulip,SmartPeople/zulip,Galexrt/zulip,arpith/zulip,brainwane/zulip,ryanbackman/zulip,zacps/zulip,andersk/zulip,brockwhittaker/zulip,paxapy/zulip,AZtheAsian/zulip,arpith/zulip,timabbott/zulip,dawran6/zulip,mahim97/zulip,grave-w-grave/zulip,arpith/zulip,amyliu345/zulip,brainwane/zulip,ryanbackman/zulip,rishig/zulip,jphilipsen05/zulip,Jianchun1/zulip,joyhchen/zulip,Galexrt/zulip,showell/zulip,jainayush975/zulip,verma-varsha/zulip,mahim97/zulip,hackerkid/zulip,showell/zulip,rishig/zulip,zulip/zulip,TigorC/zulip,rishig/zulip,aakash-cr7/zulip,joyhchen/zulip,zacps/zulip,Galexrt/zulip,jackrzhang/zulip,vabs22/zulip,jphilipsen05/zulip,dawran6/zulip,timabbott/zulip,kou/zulip,tommyip/zulip,blaze225/zulip,vikas-parashar/zulip,cosmicAsymmetry/zulip,hackerkid/zulip,shubhamdhama/zulip,dawran6/zulip,souravbadami/zulip,showell/zulip,sonali0901/zulip,JPJPJPOPOP/zulip,synicalsyntax/zulip,aakash-cr7/zulip,jainayush975/zulip,synicalsyntax/zulip,christi3k/zulip,AZtheAsian/zulip,vabs22/zulip,amyliu345/zulip,peguin40/zulip,punchagan/zulip,niftynei/zulip,AZtheAsian/zulip,dattatreya303/zulip,mahim97/zulip,Galexrt/zulip,tommyip/zulip,sharmaeklavya2/zulip,shubhamdhama/zulip,mahim97/zulip,kou/zulip,PhilSk/zulip,tommyip/zulip,rht/zulip,peguin40/zulip,samatdav/zulip,amyliu345/zulip,andersk/zulip,tommyip/zulip,Juanvulcano/zulip,mahim97/zulip,calvinleenyc/zulip,eeshangarg/zulip,PhilSk/zulip,Juanvulcano/zulip,susansls/zulip,joyhchen/zulip,sharmaeklavya2/zulip,hackerkid/zulip,AZtheAsian/zulip,zulip/zulip,rht/zulip,zulip/zulip,niftynei/zulip,aakash-cr7/zulip,Diptanshu8/zulip,reyha/zulip,KingxBanana/zulip,andersk/zulip,dhcrzf/zulip,reyha/zulip,vabs22/zulip,Diptanshu8/zulip,timabbott/zulip,punchagan/zulip,dawran6/zulip,blaze225/zulip,hackerkid/zulip,amanharitsh123/zulip,zacps/zulip,dawran6/zulip,dhcrzf/zulip,dattatreya303/zulip,jackrzhang/zulip,calvinleenyc/zulip,punchagan/zulip,amyliu345/zulip,jphilipsen05/zulip,Jianchun1/zulip,blaze225/zulip,jrowan/zulip,joyhchen/zulip,susansls/zulip,Diptanshu8/zulip,amanharitsh123/zulip,sonali0901/zulip,reyha/zulip,vikas-parashar/zulip,paxapy/zulip,punchagan/zulip,brainwane/zulip,zulip/zulip,vaidap/zulip,sharmaeklavya2/zulip,brainwane/zulip,vaidap/zulip,kou/zulip,Juanvulcano/zulip,JPJPJPOPOP/zulip,tommyip/zulip,showell/zulip,isht3/zulip,dhcrzf/zulip,souravbadami/zulip,niftynei/zulip,zacps/zulip,shubhamdhama/zulip,grave-w-grave/zulip,ryanbackman/zulip,isht3/zulip,KingxBanana/zulip,jackrzhang/zulip,isht3/zulip,jphilipsen05/zulip,rishig/zulip,souravbadami/zulip,dhcrzf/zulip,peguin40/zulip,sharmaeklavya2/zulip,KingxBanana/zulip,andersk/zulip,samatdav/zulip,ryanbackman/zulip,shubhamdhama/zulip,cosmicAsymmetry/zulip,j831/zulip,vaidap/zulip,KingxBanana/zulip,punchagan/zulip,arpith/zulip,jackrzhang/zulip,cosmicAsymmetry/zulip,samatdav/zulip,SmartPeople/zulip,zacps/zulip,synicalsyntax/zulip,reyha/zulip,verma-varsha/zulip,brainwane/zulip,timabbott/zulip,Jianchun1/zulip