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