Swift remove TableCell margin

Question

Although similar questions have been asked quite often, I still couldn't find out the exact solution. What I am trying to do now is to remove the left and right border/margin in the TableCell entirely like the below.

Existing problematic TableCell

ideal TableCell

I tried to add the below codes in func tableview (...cellForRowAt...) but it doesn't work,

    cell.separatorInset = UIEdgeInsets.zero
    cell.layoutMargins = UIEdgeInsets.zero
    cell.preservesSuperviewLayoutMargins = false

Thanks for the help!