How to use the marshmallow-sqlalchemy.schema.ModelSchemaMeta function in marshmallow-sqlalchemy

from mymodels import engine, users

        class UserSchema(TableSchema):
            class Meta:
                table = users

        schema = UserSchema()

        select = users.select().limit(1)
        user = engine.execute(select).fetchone()
        serialized = schema.dump(user).data
    """

    OPTIONS_CLASS = TableSchemaOpts

class ModelSchema(with_metaclass(ModelSchemaMeta, ma.Schema)):
    """Base class for SQLAlchemy model-based Schemas.

    Example: ::

        from marshmallow_sqlalchemy import ModelSchema
        from mymodels import User, session

        class UserSchema(ModelSchema):
            class Meta:
                model = User

        schema = UserSchema()

        user = schema.load({'name': 'Bill'}, session=session)
        existing_user = schema.load({'name': 'Bill'}, instance=User.query.first())