code: def map_exceptions(self, mapping, *args, **kwargs):
          
          @self.__call__(*args, **kwargs)
          def helper(e, status):
              return dict(exception=e), status
  
          def wrap(target):
              @wraps(target)
              def wrapper(*args, **kwargs):
                  try:
                      return target(*args, **kwargs)
                  except BaseException as e:
                      for klass, status in mapping:
                          if isinstance(e, klass):
                              return helper(e, status)
                      raise
              return wrapper
          return wrap
docs: Exception mapping helper decorator. Takes the same arguments as the
          main decorator, plus `mapping`, which is a list of
          `(exception_class, status_line)` pairs.