test points
   0 5
   0 10
   1 1
   2 2
   2 4
   3.5 8
   4 1
   4 9
   5 0
   5 1
   5 7
   5 9
   5.5 0.5
   6 1
   6 7
   6 9
   6.5 0.5
   6.5 8
   8 3
   8 6
   9 1
   9 3
test first set   (2,1),(8,7)
test operator = (2,1),(8,7)
test cctor      (2,1),(8,7)
test list insertion:
  number of successfully inserted points is 21
  LER is  (2,1),(8,7)
test default ctor    (0,0),(1,0.5)
test after removal   (2,1),(8,7)
test successful insertion 1
test after clear (0,0.5),(10,10)
test unsuccessful insertion 0
test bounding box (0,0),(10,10)
test left_bottom_right_top is 0 0,  6.5 0.5,  10 10,  0 10
