code: def get_transformer(self) -> Optional[StreamTransformer]:
      pass
  
imports: from abc import ABC, abstractmethod
  from enum import Enum
  from typing import Union, Optional
  from py4j.java_gateway import JavaObject
  from pyflink.datastream.functions import JavaFunctionWrapper
  from pyflink.java_gateway import get_gateway
label_desc: Use image node_id 1 for calling the SupportsPreprocessing obj's underlying member method code with example usage: obj.get_transformer() without return types