agent: Fix the MockEventHandler interface
agent: Fix the MockEventHandler interface

pmenglund/serf,samaitra/serf,minhkiller/serf,hashicorp/serf,jmptrader/serf,curtiszimmerman/serf,yonglehou/serf,FollowMyDev/serf,mbrukman/serf,gnawhleinad/serf,mapuri/serf,FollowMyDev/serf,mapuri/serf,dalehamel/serf,minhkiller/serf,gnawhleinad/serf,pmenglund/serf,FollowMyDev/serf,curtiszimmerman/serf,patrickviet/serf,yonglehou/serf,dalehamel/serf,patrickviet/serf,gnawhleinad/serf,yonglehou/serf,mapuri/serf,yonglehou/serf,yonglehou/serf,yonglehou/serf,patrickviet/serf,mbrukman/serf,minhkiller/serf,jmptrader/serf,dalehamel/serf,FollowMyDev/serf,minhkiller/serf,jmptrader/serf,samaitra/serf,curtiszimmerman/serf,mapuri/serf,patrickviet/serf,mapuri/serf,FollowMyDev/serf,jmptrader/serf,mbrukman/serf,dalehamel/serf,patrickviet/serf,minhkiller/serf,curtiszimmerman/serf,samaitra/serf,pmenglund/serf,hashicorp/serf,mbrukman/serf,hashicorp/serf,samaitra/serf,curtiszimmerman/serf,hashicorp/serf,dalehamel/serf,gnawhleinad/serf,minhkiller/serf,mapuri/serf,samaitra/serf,pmenglund/serf,pmenglund/serf,gnawhleinad/serf,patrickviet/serf,jmptrader/serf,mbrukman/serf,gnawhleinad/serf,samaitra/serf,curtiszimmerman/serf,mbrukman/serf,hashicorp/serf,dalehamel/serf,jmptrader/serf,pmenglund/serf,FollowMyDev/serf