find_lt<E> function
Find rightmost value less than x
Implementation
E find_lt<E>(List<E> a, E x, {Comparator<E>? compare}) {
// todo unit-test custom compare and key
int i = bisect_left(a, x, compare: compare);
if (i != 0) {
return a[i - 1];
}
throw ArgumentError('Value not found');
}