code: def create_transform(self, rule):
          
          try:
              name, value = next(iter(rule.items()))
          except AttributeError:
              name, value = rule, None
          try:
              return self.REGISTRY[name](value, conf=self.conf)
          except KeyError:
              raise RuntimeError(
                  "Unknown transform: %r" % (name,)
              )
docs: Create single transform from rule.
          Rule can be string, or {key: value} pair