/// <summary>
 /// Search hierarchy to check if child is a descendent of this.
 /// </summary>
 /// <param name="child"></param>
 /// <returns>true if child is a descendent of this cluster</returns>
 public bool Contains(CvxHull child)
 {
     if (child.Parent == null)
     {
         return(false);
     }
     if (child.Parent == this)
     {
         return(true);
     }
     return(Contains(child.Parent));
 }
 /// <summary>
 /// Search hierarchy to check if child is a descendent of this.
 /// </summary>
 /// <param name="child"></param>
 /// <returns>true if child is a descendent of this cluster</returns>
 public bool Contains(CvxHull child) {
     if (child.Parent == null) {
         return false;
     }
     if (child.Parent == this) {
         return true;
     }
     return Contains(child.Parent);
 }