Fix mistaken method name: "append", not "add"
Fix mistaken method name: "append", not "add"

This defect was originally introduced in Google-internal source control
on 18 August 2014. Wow. Clearly unit test coverage is needed for this
feature.

mehrdada/grpc,grani/grpc,malexzx/grpc,tengyifei/grpc,mway08/grpc,firebase/grpc,JoeWoo/grpc,ofrobots/grpc,jtattermusch/grpc,yang-g/grpc,andrewpollock/grpc,ipylypiv/grpc,malexzx/grpc,muxi/grpc,yinsu/grpc,deepaklukose/grpc,infinit/grpc,a11r/grpc,thinkerou/grpc,arkmaxim/grpc,zeliard/grpc,a11r/grpc,firebase/grpc,quizlet/grpc,kpayson64/grpc,kpayson64/grpc,hstefan/grpc,pszemus/grpc,mehrdada/grpc,podsvirov/grpc,rjshade/grpc,hstefan/grpc,murgatroid99/grpc,sidrakesh93/grpc,daniel-j-born/grpc,a-veitch/grpc,makdharma/grpc,meisterpeeps/grpc,yugui/grpc,dgquintas/grpc,fuchsia-mirror/third_party-grpc,VcamX/grpc,royalharsh/grpc,thunderboltsid/grpc,doubi-workshop/grpc,ofrobots/grpc,xtopsoft/grpc,andrewpollock/grpc,ipylypiv/grpc,perumaalgoog/grpc,Crevil/grpc,perumaalgoog/grpc,matt-kwong/grpc,MakMukhi/grpc,quizlet/grpc,maxwell-demon/grpc,hstefan/grpc,sreecha/grpc,stanley-cheung/grpc,dklempner/grpc,maxwell-demon/grpc,vsco/grpc,maxwell-demon/grpc,JoeWoo/grpc,larsonmpdx/grpc,greasypizza/grpc,PeterFaiman/ruby-grpc-minimal,ncteisen/grpc,yugui/grpc,madongfly/grpc,perumaalgoog/grpc,kpayson64/grpc,chrisdunelm/grpc,kpayson64/grpc,yang-g/grpc,zhimingxie/grpc,crast/grpc,y-zeng/grpc,malexzx/grpc,ppietrasa/grpc,jtattermusch/grpc,larsonmpdx/grpc,a11r/grpc,leifurhauks/grpc,baylabs/grpc,Crevil/grpc,yang-g/grpc,MakMukhi/grpc,greasypizza/grpc,tempbottle/grpc,sreecha/grpc,tamihiro/grpc,tempbottle/grpc,mehrdada/grpc,pmarks-net/grpc,deepaklukose/grpc,ipylypiv/grpc,grani/grpc,ksophocleous/grpc,maxwell-demon/grpc,vjpai/grpc,nicolasnoble/grpc,zhimingxie/grpc,JoeWoo/grpc,surround-io/grpc,sreecha/grpc,greasypizza/grpc,yugui/grpc,ipylypiv/grpc,infinit/grpc,msiedlarek/grpc,w4-sjcho/grpc,zeliard/grpc,bogdandrutu/grpc,7anner/grpc,dgquintas/grpc,stanley-cheung/grpc,chrisdunelm/grpc,jtattermusch/grpc,ctiller/grpc,msmania/grpc,grpc/grpc,kriswuollett/grpc,tempbottle/grpc,mway08/grpc,bjori/grpc,y-zeng/grpc,wcevans/grpc,kpayson64/grpc,adelez/grpc,crast/grpc,malexzx/grpc,donnadionne/grpc,wkubiak/grpc,meisterpeeps/grpc,ananthonline/grpc,ppietrasa/grpc,tempbottle/grpc,kskalski/grpc,jboeuf/grpc,yonglehou/grpc,zeliard/grpc,yinsu/grpc,w4-sjcho/grpc,daniel-j-born/grpc,ipylypiv/grpc,ncteisen/grpc,geffzhang/grpc,VcamX/grpc,yugui/grpc,ofrobots/grpc,jtattermusch/grpc,soltanmm/grpc,VcamX/grpc,wangyikai/grpc,ksophocleous/grpc,quizlet/grpc,jboeuf/grpc,ejona86/grpc,soltanmm/grpc,perumaalgoog/grpc,ncteisen/grpc,tamihiro/grpc,madongfly/grpc,hstefan/grpc,ananthonline/grpc,yonglehou/grpc,grpc/grpc,7anner/grpc,ctiller/grpc,dklempner/grpc,crast/grpc,ipylypiv/grpc,gpndata/grpc,vjpai/grpc,VcamX/grpc,deepaklukose/grpc,a11r/grpc,ncteisen/grpc,grpc/grpc,pszemus/grpc,ananthonline/grpc,wkubiak/grpc,tempbottle/grpc,sreecha/grpc,thinkerou/grpc,bjori/grpc,mway08/grpc,LuminateWireless/grpc,thinkerou/grpc,ejona86/grpc,apolcyn/grpc,greasypizza/grpc,tamihiro/grpc,makdharma/grpc,stanley-cheung/grpc,malexzx/grpc,bogdandrutu/grpc,bjori/grpc,kskalski/grpc,geffzhang/grpc,Crevil/grpc,wcevans/grpc,pmarks-net/grpc,jtattermusch/grpc,podsvirov/grpc,nicolasnoble/grpc,pmarks-net/grpc,yinsu/grpc,soltanmm-google/grpc,stanley-cheung/grpc,royalharsh/grpc,Crevil/grpc,ejona86/grpc,thinkerou/grpc,yugui/grpc,jboeuf/grpc,mehrdada/grpc,wcevans/grpc,mehrdada/grpc,grpc/grpc,jboeuf/grpc,chrisdunelm/grpc,madongfly/grpc,sidrakesh93/grpc,kskalski/grpc,kumaralokgithub/grpc,murgatroid99/grpc,surround-io/grpc,murgatroid99/grpc,tempbottle/grpc,perumaalgoog/grpc,carl-mastrangelo/grpc,rjshade/grpc,ctiller/grpc,a-veitch/grpc,pmarks-net/grpc,greasypizza/grpc,donnadionne/grpc,fuchsia-mirror/third_party-grpc,dgquintas/grpc,perumaalgoog/grpc,miselin/grpc,cgvarela/grpc,baylabs/grpc,vjpai/grpc,greasypizza/grpc,msmania/grpc,tengyifei/grpc,xtopsoft/grpc,jboeuf/grpc,JoeWoo/grpc,sidrakesh93/grpc,apolcyn/grpc,MakMukhi/grpc,xtopsoft/grpc,kskalski/grpc,bjori/grpc,kumaralokgithub/grpc,murgatroid99/grpc,PeterFaiman/ruby-grpc-minimal,soltanmm-google/grpc,baylabs/grpc,murgatroid99/grpc,yonglehou/grpc,wcevans/grpc,sreecha/grpc,PeterFaiman/ruby-grpc-minimal,philcleveland/grpc,andrewpollock/grpc,perumaalgoog/grpc,zeliard/grpc,grpc/grpc,tamihiro/grpc,grani/grpc,zeliard/grpc,tengyifei/grpc,adelez/grpc,dgquintas/grpc,soltanmm-google/grpc,ejona86/grpc,mehrdada/grpc,cgvarela/grpc,ofrobots/grpc,nicolasnoble/grpc,kriswuollett/grpc,mway08/grpc,grani/grpc,bogdandrutu/grpc,muxi/grpc,yongni/grpc,ncteisen/grpc,vjpai/grpc,madongfly/grpc,apolcyn/grpc,ananthonline/grpc,soltanmm-google/grpc,vsco/grpc,nicolasnoble/grpc,xtopsoft/grpc,wcevans/grpc,carl-mastrangelo/grpc,muxi/grpc,donnadionne/grpc,leifurhauks/grpc,leifurhauks/grpc,ejona86/grpc,leifurhauks/grpc,jcanizales/grpc,dklempner/grpc,chrisdunelm/grpc,larsonmpdx/grpc,murgatroid99/grpc,PeterFaiman/ruby-grpc-minimal,gpndata/grpc,sidrakesh93/grpc,kpayson64/grpc,philcleveland/grpc,kumaralokgithub/grpc,yugui/grpc,meisterpeeps/grpc,thinkerou/grpc,ksophocleous/grpc,pszemus/grpc,a-veitch/grpc,wcevans/grpc,VcamX/grpc,yinsu/grpc,xtopsoft/grpc,thinkerou/grpc,simonkuang/grpc,grpc/grpc,soltanmm/grpc,muxi/grpc,thunderboltsid/grpc,yongni/grpc,vsco/grpc,ctiller/grpc,msmania/grpc,infinit/grpc,firebase/grpc,pszemus/grpc,adelez/grpc,yongni/grpc,a-veitch/grpc,geffzhang/grpc,goldenbull/grpc,w4-sjcho/grpc,pszemus/grpc,soltanmm-google/grpc,ejona86/grpc,mway08/grpc,a-veitch/grpc,gpndata/grpc,zhimingxie/grpc,nicolasnoble/grpc,andrewpollock/grpc,simonkuang/grpc,baylabs/grpc,yugui/grpc,Vizerai/grpc,soltanmm/grpc,firebase/grpc,ctiller/grpc,donnadionne/grpc,grpc/grpc,philcleveland/grpc,muxi/grpc,ppietrasa/grpc,msiedlarek/grpc,miselin/grpc,soltanmm/grpc,doubi-workshop/grpc,jboeuf/grpc,nicolasnoble/grpc,LuminateWireless/grpc,bogdandrutu/grpc,larsonmpdx/grpc,jtattermusch/grpc,wcevans/grpc,mway08/grpc,sidrakesh93/grpc,daniel-j-born/grpc,surround-io/grpc,kumaralokgithub/grpc,donnadionne/grpc,ejona86/grpc,dgquintas/grpc,gpndata/grpc,gpndata/grpc,fichter/grpc,yinsu/grpc,tamihiro/grpc,y-zeng/grpc,wangyikai/grpc,arkmaxim/grpc,cgvarela/grpc,baylabs/grpc,makdharma/grpc,ananthonline/grpc,jboeuf/grpc,carl-mastrangelo/grpc,tempbottle/grpc,kumaralokgithub/grpc,a11r/grpc,soltanmm-google/grpc,ncteisen/grpc,a-veitch/grpc,matt-kwong/grpc,mehrdada/grpc,soltanmm/grpc,jboeuf/grpc,carl-mastrangelo/grpc,jcanizales/grpc,arkmaxim/grpc,firebase/grpc,ofrobots/grpc,fuchsia-mirror/third_party-grpc,wcevans/grpc,chrisdunelm/grpc,sreecha/grpc,msmania/grpc,donnadionne/grpc,nicolasnoble/grpc,apolcyn/grpc,LuminateWireless/grpc,stanley-cheung/grpc,meisterpeeps/grpc,yongni/grpc,LuminateWireless/grpc,miselin/grpc,miselin/grpc,doubi-workshop/grpc,tengyifei/grpc,hstefan/grpc,sreecha/grpc,apolcyn/grpc,donnadionne/grpc,perumaalgoog/grpc,yinsu/grpc,ejona86/grpc,adelez/grpc,jboeuf/grpc,stanley-cheung/grpc,matt-kwong/grpc,ananthonline/grpc,podsvirov/grpc,podsvirov/grpc,rjshade/grpc,yinsu/grpc,ncteisen/grpc,infinit/grpc,wangyikai/grpc,madongfly/grpc,surround-io/grpc,y-zeng/grpc,a11r/grpc,thinkerou/grpc,geffzhang/grpc,Vizerai/grpc,surround-io/grpc,pszemus/grpc,daniel-j-born/grpc,LuminateWireless/grpc,chrisdunelm/grpc,ksophocleous/grpc,VcamX/grpc,a-veitch/grpc,a11r/grpc,yonglehou/grpc,simonkuang/grpc,yang-g/grpc,kskalski/grpc,ctiller/grpc,zhimingxie/grpc,PeterFaiman/ruby-grpc-minimal,ppietrasa/grpc,arkmaxim/grpc,pmarks-net/grpc,zhimingxie/grpc,infinit/grpc,ppietrasa/grpc,daniel-j-born/grpc,carl-mastrangelo/grpc,MakMukhi/grpc,yonglehou/grpc,LuminateWireless/grpc,JoeWoo/grpc,adelez/grpc,grpc/grpc,meisterpeeps/grpc,wangyikai/grpc,vjpai/grpc,soltanmm-google/grpc,goldenbull/grpc,grpc/grpc,fichter/grpc,jtattermusch/grpc,maxwell-demon/grpc,tamihiro/grpc,kriswuollett/grpc,thinkerou/grpc,doubi-workshop/grpc,cgvarela/grpc,goldenbull/grpc,7anner/grpc,leifurhauks/grpc,surround-io/grpc,zhimingxie/grpc,sidrakesh93/grpc,yongni/grpc,geffzhang/grpc,ksophocleous/grpc,makdharma/grpc,tengyifei/grpc,PeterFaiman/ruby-grpc-minimal,gpndata/grpc,fuchsia-mirror/third_party-grpc,msmania/grpc,meisterpeeps/grpc,larsonmpdx/grpc,larsonmpdx/grpc,chrisdunelm/grpc,LuminateWireless/grpc,mway08/grpc,carl-mastrangelo/grpc,fichter/grpc,vsco/grpc,msmania/grpc,rjshade/grpc,larsonmpdx/grpc,adelez/grpc,fuchsia-mirror/third_party-grpc,w4-sjcho/grpc,ppietrasa/grpc,PeterFaiman/ruby-grpc-minimal,apolcyn/grpc,daniel-j-born/grpc,sreecha/grpc,kriswuollett/grpc,rjshade/grpc,ksophocleous/grpc,thinkerou/grpc,crast/grpc,thunderboltsid/grpc,royalharsh/grpc,nicolasnoble/grpc,thunderboltsid/grpc,dklempner/grpc,stanley-cheung/grpc,yonglehou/grpc,Vizerai/grpc,dgquintas/grpc,VcamX/grpc,wcevans/grpc,murgatroid99/grpc,royalharsh/grpc,bogdandrutu/grpc,bogdandrutu/grpc,vsco/grpc,chrisdunelm/grpc,simonkuang/grpc,jcanizales/grpc,pmarks-net/grpc,Crevil/grpc,carl-mastrangelo/grpc,msiedlarek/grpc,kpayson64/grpc,zhimingxie/grpc,quizlet/grpc,tempbottle/grpc,ctiller/grpc,baylabs/grpc,yinsu/grpc,doubi-workshop/grpc,Vizerai/grpc,wangyikai/grpc,jcanizales/grpc,simonkuang/grpc,bogdandrutu/grpc,ctiller/grpc,madongfly/grpc,kriswuollett/grpc,mehrdada/grpc,philcleveland/grpc,apolcyn/grpc,tengyifei/grpc,nicolasnoble/grpc,madongfly/grpc,sidrakesh93/grpc,philcleveland/grpc,7anner/grpc,wangyikai/grpc,cgvarela/grpc,pszemus/grpc,soltanmm-google/grpc,wangyikai/grpc,fuchsia-mirror/third_party-grpc,Vizerai/grpc,goldenbull/grpc,dklempner/grpc,grani/grpc,thinkerou/grpc,goldenbull/grpc,madongfly/grpc,doubi-workshop/grpc,matt-kwong/grpc,stanley-cheung/grpc,thunderboltsid/grpc,simonkuang/grpc,podsvirov/grpc,jcanizales/grpc,goldenbull/grpc,yugui/grpc,donnadionne/grpc,a11r/grpc,donnadionne/grpc,vsco/grpc,royalharsh/grpc,xtopsoft/grpc,kpayson64/grpc,arkmaxim/grpc,JoeWoo/grpc,7anner/grpc,MakMukhi/grpc,fuchsia-mirror/third_party-grpc,leifurhauks/grpc,chrisdunelm/grpc,leifurhauks/grpc,mway08/grpc,bogdandrutu/grpc,makdharma/grpc,firebase/grpc,infinit/grpc,makdharma/grpc,jcanizales/grpc,carl-mastrangelo/grpc,ncteisen/grpc,zeliard/grpc,hstefan/grpc,chrisdunelm/grpc,maxwell-demon/grpc,yongni/grpc,vjpai/grpc,msiedlarek/grpc,deepaklukose/grpc,fuchsia-mirror/third_party-grpc,daniel-j-born/grpc,philcleveland/grpc,vjpai/grpc,rjshade/grpc,tamihiro/grpc,grani/grpc,yang-g/grpc,jcanizales/grpc,msiedlarek/grpc,y-zeng/grpc,jboeuf/grpc,tengyifei/grpc,andrewpollock/grpc,jtattermusch/grpc,y-zeng/grpc,ctiller/grpc,grpc/grpc,leifurhauks/grpc,ofrobots/grpc,maxwell-demon/grpc,yonglehou/grpc,jboeuf/grpc,grani/grpc,dgquintas/grpc,quizlet/grpc,podsvirov/grpc,miselin/grpc,thunderboltsid/grpc,7anner/grpc,7anner/grpc,doubi-workshop/grpc,sreecha/grpc,PeterFaiman/ruby-grpc-minimal,ananthonline/grpc,deepaklukose/grpc,pszemus/grpc,soltanmm-google/grpc,deepaklukose/grpc,quizlet/grpc,kumaralokgithub/grpc,vjpai/grpc,vjpai/grpc,arkmaxim/grpc,yang-g/grpc,goldenbull/grpc,matt-kwong/grpc,Vizerai/grpc,firebase/grpc,stanley-cheung/grpc,stanley-cheung/grpc,royalharsh/grpc,ctiller/grpc,jcanizales/grpc,w4-sjcho/grpc,tamihiro/grpc,ncteisen/grpc,zeliard/grpc,msiedlarek/grpc,dgquintas/grpc,crast/grpc,dgquintas/grpc,miselin/grpc,ncteisen/grpc,a11r/grpc,bjori/grpc,xtopsoft/grpc,wangyikai/grpc,ofrobots/grpc,adelez/grpc,kpayson64/grpc,pmarks-net/grpc,thinkerou/grpc,bjori/grpc,cgvarela/grpc,greasypizza/grpc,Vizerai/grpc,simonkuang/grpc,kumaralokgithub/grpc,ctiller/grpc,kriswuollett/grpc,carl-mastrangelo/grpc,mehrdada/grpc,matt-kwong/grpc,andrewpollock/grpc,kumaralokgithub/grpc,makdharma/grpc,msiedlarek/grpc,infinit/grpc,VcamX/grpc,kskalski/grpc,vjpai/grpc,carl-mastrangelo/grpc,hstefan/grpc,matt-kwong/grpc,bjori/grpc,dklempner/grpc,Crevil/grpc,thunderboltsid/grpc,geffzhang/grpc,malexzx/grpc,zeliard/grpc,w4-sjcho/grpc,soltanmm/grpc,ofrobots/grpc,geffzhang/grpc,vjpai/grpc,arkmaxim/grpc,ejona86/grpc,yongni/grpc,matt-kwong/grpc,msmania/grpc,makdharma/grpc,tengyifei/grpc,deepaklukose/grpc,baylabs/grpc,kskalski/grpc,a-veitch/grpc,royalharsh/grpc,mehrdada/grpc,crast/grpc,fichter/grpc,soltanmm/grpc,arkmaxim/grpc,donnadionne/grpc,sreecha/grpc,jcanizales/grpc,y-zeng/grpc,JoeWoo/grpc,JoeWoo/grpc,muxi/grpc,apolcyn/grpc,yugui/grpc,pszemus/grpc,hstefan/grpc,jtattermusch/grpc,daniel-j-born/grpc,adelez/grpc,yinsu/grpc,infinit/grpc,fichter/grpc,vsco/grpc,apolcyn/grpc,andrewpollock/grpc,sreecha/grpc,grpc/grpc,Vizerai/grpc,pmarks-net/grpc,rjshade/grpc,bjori/grpc,gpndata/grpc,yongni/grpc,maxwell-demon/grpc,tengyifei/grpc,simonkuang/grpc,larsonmpdx/grpc,a-veitch/grpc,greasypizza/grpc,ejona86/grpc,yang-g/grpc,mehrdada/grpc,ppietrasa/grpc,muxi/grpc,vsco/grpc,VcamX/grpc,pszemus/grpc,podsvirov/grpc,y-zeng/grpc,arkmaxim/grpc,ofrobots/grpc,bogdandrutu/grpc,w4-sjcho/grpc,muxi/grpc,chrisdunelm/grpc,ananthonline/grpc,podsvirov/grpc,firebase/grpc,kumaralokgithub/grpc,dklempner/grpc,doubi-workshop/grpc,MakMukhi/grpc,Crevil/grpc,wkubiak/grpc,Vizerai/grpc,xtopsoft/grpc,donnadionne/grpc,vjpai/grpc,wkubiak/grpc,crast/grpc,kriswuollett/grpc,greasypizza/grpc,MakMukhi/grpc,stanley-cheung/grpc,kskalski/grpc,carl-mastrangelo/grpc,y-zeng/grpc,cgvarela/grpc,MakMukhi/grpc,ppietrasa/grpc,w4-sjcho/grpc,thunderboltsid/grpc,rjshade/grpc,cgvarela/grpc,ctiller/grpc,LuminateWireless/grpc,hstefan/grpc,daniel-j-born/grpc,msiedlarek/grpc,ejona86/grpc,madongfly/grpc,7anner/grpc,msiedlarek/grpc,andrewpollock/grpc,thunderboltsid/grpc,philcleveland/grpc,ncteisen/grpc,msmania/grpc,fichter/grpc,geffzhang/grpc,w4-sjcho/grpc,sreecha/grpc,msmania/grpc,yonglehou/grpc,malexzx/grpc,leifurhauks/grpc,stanley-cheung/grpc,ejona86/grpc,podsvirov/grpc,muxi/grpc,perumaalgoog/grpc,ananthonline/grpc,nicolasnoble/grpc,baylabs/grpc,yang-g/grpc,muxi/grpc,grpc/grpc,ksophocleous/grpc,dgquintas/grpc,doubi-workshop/grpc,royalharsh/grpc,grani/grpc,simonkuang/grpc,infinit/grpc,jtattermusch/grpc,firebase/grpc,Vizerai/grpc,Crevil/grpc,surround-io/grpc,ipylypiv/grpc,jboeuf/grpc,Vizerai/grpc,murgatroid99/grpc,malexzx/grpc,tamihiro/grpc,murgatroid99/grpc,nicolasnoble/grpc,miselin/grpc,quizlet/grpc,carl-mastrangelo/grpc,firebase/grpc,wkubiak/grpc,geffzhang/grpc,JoeWoo/grpc,philcleveland/grpc,muxi/grpc,kpayson64/grpc,royalharsh/grpc,philcleveland/grpc,soltanmm/grpc,firebase/grpc,fichter/grpc,kskalski/grpc,larsonmpdx/grpc,jtattermusch/grpc,yongni/grpc,grani/grpc,maxwell-demon/grpc,zhimingxie/grpc,fuchsia-mirror/third_party-grpc,sidrakesh93/grpc,kriswuollett/grpc,bjori/grpc,fuchsia-mirror/third_party-grpc,Crevil/grpc,ncteisen/grpc,miselin/grpc,PeterFaiman/ruby-grpc-minimal,crast/grpc,LuminateWireless/grpc,ksophocleous/grpc,malexzx/grpc,kpayson64/grpc,makdharma/grpc,murgatroid99/grpc,pszemus/grpc,jtattermusch/grpc,gpndata/grpc,deepaklukose/grpc,goldenbull/grpc,7anner/grpc,deepaklukose/grpc,matt-kwong/grpc,mehrdada/grpc,surround-io/grpc,adelez/grpc,muxi/grpc,yang-g/grpc,wkubiak/grpc,MakMukhi/grpc,quizlet/grpc,fichter/grpc,wkubiak/grpc,dklempner/grpc,ipylypiv/grpc,andrewpollock/grpc,pszemus/grpc,thinkerou/grpc,dklempner/grpc,zhimingxie/grpc,kriswuollett/grpc,quizlet/grpc,baylabs/grpc,miselin/grpc,wangyikai/grpc,goldenbull/grpc,pmarks-net/grpc,nicolasnoble/grpc,firebase/grpc,meisterpeeps/grpc,dgquintas/grpc,rjshade/grpc,PeterFaiman/ruby-grpc-minimal,ppietrasa/grpc,donnadionne/grpc,meisterpeeps/grpc,wkubiak/grpc,vsco/grpc,ipylypiv/grpc