Execution example::

  tokenize TokenBigram "日 本 語 ! ! !" NormalizerAuto
  # [
  #   [
  #     0, 
  #     1337566253.89858, 
  #     0.000355720520019531
  #   ], 
  #   [
  #     {
  #       "position": 0, 
  #       "force_prefix": false, 
  #       "value": "日"
  #     }, 
  #     {
  #       "position": 1, 
  #       "force_prefix": false, 
  #       "value": "本"
  #     }, 
  #     {
  #       "position": 2, 
  #       "force_prefix": false, 
  #       "value": "語"
  #     }, 
  #     {
  #       "position": 3, 
  #       "force_prefix": false, 
  #       "value": "!"
  #     }, 
  #     {
  #       "position": 4, 
  #       "force_prefix": false, 
  #       "value": "!"
  #     }, 
  #     {
  #       "position": 5, 
  #       "force_prefix": false, 
  #       "value": "!"
  #     }
  #   ]
  # ]
