1. override
TableBorder scale(double t)

Creates a new border with the widths of this border multiplied by t.

Source 

@override
TableBorder scale(double t) {
  return new TableBorder(
    top: top.copyWith(width: t * top.width),
    right: right.copyWith(width: t * right.width),
    bottom: bottom.copyWith(width: t * bottom.width),
    left: left.copyWith(width: t * left.width),
    horizontalInside: horizontalInside.copyWith(width: t * horizontalInside.width),
    verticalInside: verticalInside.copyWith(width: t * verticalInside.width)
  );
}