code: def transform(function):
          
          def transform_fn(_, result):
              if isinstance(result, Nothing):
                  return result
  
              lgr.debug("Transforming %r with %r", result, function)
              try:
                  return function(result)
              except:
                  exctype, value, tb = sys.exc_info()
                  try:
                      new_exc = StyleFunctionError(function, exctype, value)
                      # Remove the "During handling ..." since we're
                      # reraising with the traceback.
                      new_exc.__cause__ = None
                      six.reraise(StyleFunctionError, new_exc, tb)
                  finally:
                      # Remove circular reference.
                      # https://docs.python.org/2/library/sys.html#sys.exc_info
                      del tb
          return transform_fn
docs: Return a processor for a style's "transform" function.