code: def set_verbosity(self, verbose=False, print_func=None):
          
          self._verbose = verbose
          if print_func is None:
              def asum_stat(x):
                  """returns |x|/size(x), async execution."""
                  return str((ndarray.norm(x)/sqrt(x.size)).asscalar())
              print_func = asum_stat
          self._print_func = print_func
          return self
docs: Switch on/off verbose mode
  
          Parameters
          ----------
          verbose : bool
              switch on/off verbose mode
          print_func : function
              A function that computes statistics of initialized arrays.
              Takes an `NDArray` and returns an `str`. Defaults to mean
              absolute value str((abs(x)/size(x)).asscalar()).