private RandomAccessSequence(FingerTreeSized <Element> ft)
{
_ft = ft;
}
/// <summary>
/// Initializes a new instance of the <see cref="RandomAccessSequence{T}"/> struct
/// containing the same elements as <paramref name="sequence"/>.
/// </summary>
/// <param name="sequence">The original sequence.</param>
internal RandomAccessSequence(IEnumerable <T> sequence)
{
_ft = _emptyInstance._ft.AppendRange(sequence.Map(x => new Element(x)));
}
