Similar to create. But the transaction is not committed

        Args:

            **kwargs : The keyword arguments for the constructor

        Returns:

            A model instance which has been added to db session. But session
            transaction has not been committed yet.

def build(cls, **kwargs):
        """Similar to create. But the transaction is not committed

        Args:

            **kwargs : The keyword arguments for the constructor

        Returns:

            A model instance which has been added to db session. But session
            transaction has not been committed yet.
        """
        return cls.add(cls.new(**kwargs), commit=False)