/// <summary>
/// Removes the element at some index from the list.
/// </summary>
/// <param name="index"> The index to remove. </param>
/// <exception cref="ArgumentOutOfRangeException">Thrown if the index does not exist in the list.</exception>
/// <returns> </returns>
public ImmList <T> RemoveAt(int index)
{
index.CheckIsBetween("index", -Root.Measure, Root.Measure - 1);
index = index < 0 ? index + Root.Measure : index;
var ret = Root.RemoveAt(index, Lineage.Mutable()).Wrap();
#if ASSERTS
if (Root.Measure > index + 1)
{
ret[index].AssertEqual(this[index + 1]);
}
ret.Root.Measure.AssertEqual(Root.Measure - 1);
#endif
return(ret);
}