sortOrdered method
Sorts this list according to the order specified by the compare
function.
This is similar to sort, but uses a merge sort algorithm.
Contrary to sort, orderedSort
is stable, meaning distinct objects
that compare as equal end up in the same order as they started in.
Implementation
void sortOrdered([int Function(T a, T b)? compare]) {
mergeSort<T>(this, compare: compare);
}