<s> """<STR_LIT>""" <EOL> from django . db import models <EOL> class Owner ( models . Model ) : <EOL> pass <EOL> class Animal ( models . Model ) : <EOL> owner = models . ForeignKey ( Owner , blank = True , null = True ) <EOL> class Thing ( models . Model ) : <EOL> owner = models . ForeignKey ( Owner ) </s>
