code: def handler(init, exposes, version=None):
      
      return StorableHandler(poke=poke(exposes), peek=peek(init, exposes), version=version)
docs: Simple handler with default `peek` and `poke` procedures.
  
      Arguments:
  
          init (callable): type constructor.
  
          exposes (iterable): attributes to be (de-)serialized.
  
          version (tuple): version number.
  
      Returns:
  
          StorableHandler: storable handler.