/// <summary>
 /// Mirrors the specified segment about the x-axis.
 /// </summary>
 /// <returns>IPathSegment.</returns>
 public virtual IPathSegment MirrorAboutAxisX()
 {
     return(new LineSegment(
                CartesianCoordinate.MirrorAboutAxisX(I),
                CartesianCoordinate.MirrorAboutAxisX(J)));
 }