logTime<R> function
Implementation
R logTime<R>(String? name, R cb()) {
if (name == null) return cb();
final a1 = DateTime.now().millisecondsSinceEpoch;
final result = cb();
final a2 = DateTime.now().millisecondsSinceEpoch;
print('$name: ${a2 - a1}ms');
return result;
}