text: from typing import Callable
  
  def load(data: int,
           output: Callable[[str, str], None],
           error: Callable[[str, Exception], None]):
      try:
          print('load')
          # TODO: Load data...
          output('OUT', str(data))
      except Exception as e:
          error('ERR', e)
  
  def show(data: str,
           output: Callable[[str, str], None],
           error: Callable[[str, Exception], None]):
      try:
          print('show')
          # TODO: Load data...
          output('OUT', data)
      except Exception as e:
          error('ERR', e)
  
  def error(data: Exception,
            output: Callable[[str, str], None],
            error: Callable[[str, Exception], None]):
      print(data)