evolution_chain_id = Column(Integer, ForeignKey('evolution_chains.id'), nullable=False)
evolution_parent_pokemon_id = Column(Integer, ForeignKey('pokemon.id'))
evolution_method_id = Column(Integer, ForeignKey('evolution_methods.id'))
evolution_chain_id = Column(Integer, ForeignKey('evolution_chains.id'), nullable=False)
evolution_parent_pokemon_id = Column(Integer, ForeignKey('pokemon.id'))
evolution_method_id = Column(Integer, ForeignKey('evolution_methods.id'))