/// <summary>
 /// Compares two objects for geometric equality
 /// </summary>
 /// <param name="a"></param>
 /// <param name="b">object to compare with</param>
 /// <returns></returns>
 public static bool GeometricEquals(this IfcPolyline a, IfcPolyline b)
 {
     if (a.Equals(b)) return true;
     if (a.Points.Count != b.Points.Count) return false;
     for (int i = 0; i < a.Points.Count; i++)
         if (!a.Points[i].GeometricEquals(b.Points[i])) return false; //dioes not deal with plines that have the same points but with a different start point
     return true;
 }
 public IXbimFace CreateFace(IfcPolyline pline)
 {
     return _engine.CreateFace(pline);
 }