'Returns dates based on number of days configured in current lot\'s product.'

def _get_dates(self, product_id=None):

    mapped_fields = {'life_date': 'life_time', 'use_date': 'use_time', 'removal_date': 'removal_time', 'alert_date': 'alert_time'}
    res = dict.fromkeys(mapped_fields.keys(), False)
    product = (self.env['product.product'].browse(product_id) or self.product_id)
    if product:
        for field in mapped_fields.keys():
            duration = getattr(product, mapped_fields[field])
            if duration:
                date = (datetime.datetime.now() + datetime.timedelta(days=duration))
                res[field] = fields.Datetime.to_string(date)
    return res
