code: def pop_parameter(key):
      '''Remove and get parameter by key.
  
      Args:
          key(str): Key of parameter.
  
      Returns: ~nnabla.Variable
          Parameter if key found, otherwise None.
  
      '''
      names = key.split('/')
      if len(names) > 1:
          with parameter_scope(names[0]):
              return pop_parameter('/'.join(names[1:]))
      global current_scope
      param = current_scope.get(key, None)
      if param is not None:
          del current_scope[key]
      return paraf pop_parameter(key):
      '''Remove and get parameter by key.
  
      Args:
          key(str): Key of parameter.
  
      Returns: ~nnabla.Variable
          Parameter if key found, otherwise None.
  
      '''
      names = key.split('/')
      if len(names) > 1:
          with parameter_scope(names[0]):
              return pop_parameter('/'.join(names[1:]))
      global current_scope
      param = current_scope.get(key, None)
      if param is not None:
          del current_scope[key]
      return param
docs: Remove and get parameter by key.
  
      Args:
          key(str): Key of parameter.
  
      Returns: ~nnabla.Variable
          Parameter if key found, otherwise None.