/// <summary>
/// Constructs a new index.
/// </summary>
/// <param name="x">The x value.</param>
/// <param name="yz">The x and y values.</param>
public LongIndex3D(long x, LongIndex2D yz)
: this(x, yz.X, yz.Y)
{
}
/// <summary>
/// Constructs a new index.
/// </summary>
/// <param name="xy">The x and y values.</param>
/// <param name="z">The z value.</param>
public LongIndex3D(LongIndex2D xy, long z)
: this(xy.X, xy.Y, z)
{
}