top method
Returns (value, count). Deterministic tie-break by lexicographic toString.
Implementation
(T, int)? top() {
if (_counts.isEmpty) return null;
final entries =
_counts.entries.toList()..sort((a, b) {
final byCount = b.value.compareTo(a.value);
if (byCount != 0) return byCount;
return a.key.toString().compareTo(b.key.toString());
});
final e = entries.first;
return (e.key, e.value);
}