使用marshmallow_sqlalchemy的不可为空的自动递增整数外键

如何解决使用marshmallow_sqlalchemy的不可为空的自动递增整数外键

这是该问题的MWE：

from sqlalchemy import Column,ForeignKey
from sqlalchemy import INTEGER
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from marshmallow_sqlalchemy import sqlAlchemyAutoSchema

Base = declarative_base()

class TableA(Base):
    __tablename__ = "TableA"
    id = Column(INTEGER,primary_key=True)
    other_id = Column(INTEGER,ForeignKey("TableB.id"),nullable=False)
    tableb = relationship("TableB")
    
    
class TableB(Base):
    __tablename__ = "TableB"
    id = Column(INTEGER,primary_key=True)
    tablea = relationship("TableA")


class BaseSchema(sqlAlchemyAutoSchema):
    class Meta:
        include_relationships = True
        load_instance = True
        include_fk = True
        transient = True

class TableASchema(BaseSchema):
    class Meta(BaseSchema.Meta):
        model = TableA
        
class TableBSchema(BaseSchema):
    class Meta(BaseSchema.Meta):
        model = TableB


b = TableBSchema().load({})
a = TableASchema().load({"tableb": b,"other_id": b.id})

哪个会导致：

ValidationError: {'other_id': ['Field may not be null.']}

如何在提交/刷新之前实例化这种外键关系？我需要做成千上万次，因此每次冲洗都将永远花费。