+Nature.decreased_stat = relation(Stat, primaryjoin=Nature.decreased_stat_id==Stat.id,
+ backref='decreasing_natures')
+Nature.increased_stat = relation(Stat, primaryjoin=Nature.increased_stat_id==Stat.id,
+ backref='increasing_natures')
+
+Pokedex.region = relation(Region, backref='pokedexes')
+Pokedex.version_groups = relation(VersionGroup, secondary=PokedexVersionGroup.__table__, backref='pokedexes')