/// <summary>
/// Creates a new rope and initializes it with a part of this rope.
/// Runs in O(lg N) plus a per-node cost as if <c>this.Clone()</c> was called.
/// </summary>
/// <exception cref="ArgumentOutOfRangeException">offset or length is outside the valid range.</exception>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public Rope<T> GetRange(int index, int count)
{
VerifyRange(index, count);
Rope<T> newRope = Clone();
int endIndex = index + count;
newRope.RemoveRange(endIndex, newRope.Length - endIndex);
newRope.RemoveRange(0, index);
return newRope;
}