old_contents: from functools import wraps
  
  from chainer import cuda
  from chainer import Variable
  import numpy as np
  
  def wrap_variable(func):
      @wraps(func)
      def wrapper(*args, **kwargs):
          result = func(*args, **kwargs)
          return Variable(result)
  
  class xpmeta(type):
      def __new__(cls, clsname, bases, clsdict):
          try:
              cuda.check_cuda_available()
              xp = cuda.cupy
          except RuntimeError:
              xp = np
          return xp
  
  class xp(metaclass=xpmeta):
      pass
  
new_contents: from functools import wraps
  
  from chainer import cuda
  from chainer import Variable
  import numpy as np
  
  def wrap_variable(func):
      @wraps(func)
      def wrapper(*args, **kwargs):
          result = func(*args, **kwargs)
          return Variable(result)
      return wrapper
  
  class xpmeta(type):
      def __new__(cls, clsname, bases, clsdict):
          try:
              cuda.check_cuda_available()
              xp = cuda.cupy
          except RuntimeError:
              xp = np
          return xp
  
  class xp(metaclass=xpmeta):
      pass
  
subject: update wrapper.py