use respond_to? instead of is_a? to check primary_key
use respond_to? instead of is_a? to check primary_key

theass/bullet,yakovenkodenis/bullet,eileencodes/bullet,PikachuEXE/bullet,rstacruz/bullet,eileencodes/bullet,flyerhzm/bullet,hannahbot/bullet,danp60/bullet,jay3126/bullet,sideci-sample/sideci-sample-bullet,jay3126/bullet,sideci-sample/sideci-sample-bullet,theass/bullet,flyerhzm/bullet,rrosenblum/bullet,sho-h/brakefast,rstacruz/bullet,dwb/bullet,hannahbot/bullet,sho-h/brakefast,rrosenblum/bullet,dwb/bullet,danp60/bullet,PikachuEXE/bullet,yakovenkodenis/bullet,flyerhzm/bullet