substringSafe method
Implementation
String substringSafe(int start, [int? end]) {
if (this == null || this!.isEmpty) return '';
final s = this!;
final safeStart = start.clamp(0, s.length);
final safeEnd = end != null ? end.clamp(0, s.length) : s.length;
if (safeStart >= safeEnd) return '';
return s.substring(safeStart, safeEnd);
}