Number.toRoman

Convert number to a Roman numeral.

The value must be an integer greater than zero, or an error will be thrown.

$num = 7
$num.toRoman()  //= 'VII'

$num = 19
$num.toRoman()  //= 'XIX'

$num = 1234
$num.toRoman()  //= 'MCCXXXIV'