1 1
   2 2
   3 toString called
   4 toString called
   5 3
   6 toString called
   7 true
   8 toString called
   9 true
  10 toString called
  11 true
  12 toString called
  13 undefined
  14 a
  15 b
  16 toString called
  17 c
  18 toString called
  19 3
  20 toString called
  21 toString called
  22 undefined 3
  23 undefined
  24 1
  25 false
  26 true
  27 true
  28 1
  29 true
  30 undefined
  31 1
  32 undefined
  33 true
  34 false
  35 true
  36 1
  37 true
  38 undefined