public static String toRoman(final int number, final int[][] digits,
                               final String zero, final String[] letters) {
        int maxVal = maxLetterValue(letters);
        return toRoman(new StringBuilder(), number, digits, zero, letters, maxVal).toString();
    }
public static String toRoman ( final int number , final int [ ] [ ] digits , final String zero , final String [ ] letters ) { int maxVal = maxLetterValue ( letters ) ; return toRoman ( new StringBuilder ( ) , number , digits , zero , letters , maxVal ) . toString ( ) ; }
Converts an integer into a roman number.

@param number    the value to convert
@param digits    digit codes,
i.e. {@link Romans#DIGITS DIGITS} or
{@link Romans#DIGITS_SIMPLE DIGITS_SIMPLE}
@param zero      representation of zero or {@code null}
@param letters   letters to use for roman number
@throws IllegalArgumentException if {@code number} is negative or
too large to be represented with the given letters or if
{@code number} is 0 and {@code zero} is null.