1 hello
   2 hello
   3 33
   4 33
   5 foo
   6 foo
   7 bar
   8 bar
   9 343
  10 343
  11 3.14
  12 3.14
  13 key.toString called
  14 key.toString called
  15 value
  16 value
  17 foo
  18 foo
  19 bar
  20 bar