/// <summary>
/// Merge sorts list of elements. Can be chosen if topDown or BottomUp by passing true or false value as argument to the method. By default it is topDown
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="collection">List of elements</param>
/// <param name="isTopDown">true or false whether is top down or bottom up</param>
private static void MergeSort <T>(IList <T> collection, bool isTopDown = true)
where T : IComparable
{
MergeSorter sorter = new MergeSorter();
var returned = sorter.SplitThenSort(collection, isTopDown);
PrintCollection(returned);
}