We have a field that is defined like this on the product.template model: 

fields.Char(        string='MPN',        compute='_compute_mpn',        inverse='_inverse_mpn',        store=True,    )

And like this on the product.product model: 

fields.Char(string='MPN')

Now when I import this field, it doesn't show any errors but doesn't get imported either, the field stays blank. Is there anything special that needs to be done to make this import work?