public NpgsqlLSeg(double startx, double starty, double endx, double endy) : this()
 {
     Start = new NpgsqlPoint(startx, starty);
     End   = new NpgsqlPoint(endx, endy);
 }
 public NpgsqlBox(NpgsqlPoint upperRight, NpgsqlPoint lowerLeft) : this()
 {
     UpperRight = upperRight;
     LowerLeft  = lowerLeft;
 }
 public NpgsqlLSeg(NpgsqlPoint start, NpgsqlPoint end)
     : this()
 {
     Start = start;
     End   = end;
 }