}
public static String formatSafetyNumber(String digits) {
+ if (digits == null) {
+ return null;
+ }
+
final var partCount = 12;
var partSize = digits.length() / partCount;
var f = new StringBuilder(digits.length() + partCount);
for (var i = 0; i < partCount; i++) {
- f.append(digits, i * partSize, (i * partSize) + partSize).append(" ");
+ f.append(digits, i * partSize, (i * partSize) + partSize);
+ if (i != partCount - 1) {
+ f.append(" ");
+ }
}
return f.toString();
}