MarshmallowSqlalchemy issue with one/many to zero/one using sqlalchemy's uselist=False

marshmallow_sqlalchemy_issue_one_or_many_to_zero_or_one.py

import sqlalchemy as sa
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import scoped_session, sessionmaker, relationship
from sqlalchemy.ext.hybrid import hybrid_property
from marshmallow_sqlalchemy import ModelSchema

engine = sa.create_engine('sqlite:///:memory:')
session = scoped_session(sessionmaker(bind=engine))
Base = declarative_base()

class Author(Base):
    __tablename__ = 'authors'
    id = sa.Column(sa.Integer, primary_key=True)
    name = sa.Column(sa.String)

    featuring = relationship('FeaturedAuthor', uselist=False,
                             backref='author')

    @hybrid_property
    def featured(self):
        if self.featuring is not None:
            return True
        return False

    @featured.expression
    def featured(cls):
        if cls.featuring is not None:
            return True
        return False

    def __repr__(self):
        return '<Author(name={self.name!r})>'.format(self=self)

class FeaturedAuthor(Base):
    __tablename__ = 'featuredauthors'
    id = sa.Column(sa.Integer, sa.ForeignKey('authors.id'), primary_key=True)

Base.metadata.create_all(engine)

class AuthorSchema(ModelSchema):
    class Meta:
        model = Author
        sqla_session = session

author_schema = AuthorSchema()

author = Author(name='Chuck Paluhniuk')
# featured_author = FeaturedAuthor(author=author)
session.add(author)
# session.add(featured_author)
session.commit()

print 'Featured:', author.featured
print
data_dump = author_schema.dump(author).data
print data_dump

data, error = author_schema.load(data_dump)