code: def construct_exc_class(cls):
      
  
      class ProxyException(cls, BaseException):
          __pep3134__ = True
  
          @property
          def __traceback__(self):
              if self.__fixed_traceback__:
                  return self.__fixed_traceback__
  
              current_exc, current_tb = sys.exc_info()[1:]
              if current_exc is self:
                  return current_tb
  
          def __init__(self, instance=None):  # pylint: disable=W0231
              self.__original_exception__ = instance
              self.__fixed_traceback__ = None
  
          def __getattr__(self, item):
              return getattr(self.__original_exception__, item)
  
          def __repr__(self):
              return repr(self.__original_exception__)
  
          def __str__(self):
              return str(self.__original_exception__)
  
          def with_traceback(self, traceback):
              instance = copy.copy(self)
              instance.__fixed_traceback__ = traceback
              return instance
  
      ProxyException.__name__ = cls.__name__
  
      return ProxyException
docs: Constructs proxy class for the exception.