flow_table: Compare to None using is/is not
flow_table: Compare to None using is/is not

denovogroup/pox,noxrepo/pox,VamsikrishnaNallabothu/pox,jacobq/csci5221-viro-project,xAKLx/pox,adusia/pox,PrincetonUniversity/pox,PrincetonUniversity/pox,waltznetworks/pox,carlye566/IoT-POX,chenyuntc/pox,waltznetworks/pox,adusia/pox,waltznetworks/pox,MurphyMc/pox,VamsikrishnaNallabothu/pox,andiwundsam/_of_normalize,xAKLx/pox,adusia/pox,jacobq/csci5221-viro-project,andiwundsam/_of_normalize,pthien92/sdn,chenyuntc/pox,kulawczukmarcin/mypox,MurphyMc/pox,kpengboy/pox-exercise,jacobq/csci5221-viro-project,MurphyMc/pox,MurphyMc/pox,xAKLx/pox,noxrepo/pox,diogommartins/pox,PrincetonUniversity/pox,VamsikrishnaNallabothu/pox,PrincetonUniversity/pox,diogommartins/pox,noxrepo/pox,chenyuntc/pox,noxrepo/pox,jacobq/csci5221-viro-project,carlye566/IoT-POX,waltznetworks/pox,jacobq/csci5221-viro-project,chenyuntc/pox,VamsikrishnaNallabothu/pox,xAKLx/pox,carlye566/IoT-POX,kulawczukmarcin/mypox,kpengboy/pox-exercise,kpengboy/pox-exercise,PrincetonUniversity/pox,denovogroup/pox,denovogroup/pox,kulawczukmarcin/mypox,pthien92/sdn,kpengboy/pox-exercise,adusia/pox,waltznetworks/pox,andiwundsam/_of_normalize,carlye566/IoT-POX,diogommartins/pox,chenyuntc/pox,diogommartins/pox,kulawczukmarcin/mypox,pthien92/sdn,kulawczukmarcin/mypox,pthien92/sdn,kpengboy/pox-exercise,denovogroup/pox,pthien92/sdn,carlye566/IoT-POX,andiwundsam/_of_normalize,xAKLx/pox,VamsikrishnaNallabothu/pox,diogommartins/pox,MurphyMc/pox,adusia/pox,denovogroup/pox