ps = ProductStock.objects.filter(line_albaran=self.object).first()
        if ps:
            # initial field
            form.fields['storage'].initial = ps.batch.zone.storage
            form.fields['zone'].initial = ps.batch.zone
            form.fields['batch'].initial = ps.batch

def get_form(self, form_class=None):
        form = super(LineAlbaranUpdate, self).get_form(form_class)

        raise Exception("Cambiar ProductStock por ProductUnique")
        """
        ps = ProductStock.objects.filter(line_albaran=self.object).first()
        if ps:
            # initial field
            form.fields['storage'].initial = ps.batch.zone.storage
            form.fields['zone'].initial = ps.batch.zone
            form.fields['batch'].initial = ps.batch
        """
        return form