} //EndMethod
public IEnumerable <int> SimpleListConcatArray()
{
return(SimpleListItems.Concat(ArrayItems2).Reverse());
} //EndMethod
} //EndMethod
public IEnumerable <int> SimpleListConcatArray()
{
return(SimpleListItems.Concat(ArrayItems2).GroupBy(x => x % 10, x => x, (x, y) => y.Sum()));
} //EndMethod
