code: def __init__(self, serialized_fn, operator_state_backend):
      super(StatelessOperation, self).__init__(
          serialized_fn, operator_state_backend
      )
      (
          self.open_func,
          self.close_func,
          self.process_element_func,
      ) = extract_stateless_function(
          user_defined_function_proto=serialized_fn,
          runtime_context=StreamingRuntimeContext.of(
              serialized_fn.runtime_context, self.base_metric_group
          ),
          operator_state_store=operator_state_backend,
      )
  
imports: import abc
  from typing import cast
  from pyflink.common import Row
  from pyflink.common.serializer import VoidNamespaceSerializer
  from pyflink.datastream import TimeDomain, RuntimeContext
  from pyflink.datastream.functions import BroadcastProcessFunction
  from pyflink.datastream.window import WindowOperationDescriptor
  from pyflink.fn_execution import pickle
  from pyflink.fn_execution.datastream.process.input_handler import RunnerInputHandler, TimerHandler, _emit_results
  from pyflink.fn_execution.datastream import operations
  from pyflink.fn_execution.datastream.process.runtime_context import StreamingRuntimeContext
  from pyflink.fn_execution.datastream.process.process_function import InternalKeyedProcessFunctionOnTimerContext, InternalKeyedProcessFunctionContext, InternalProcessFunctionContext, InternalBroadcastProcessFunctionContext, InternalBroadcastProcessFunctionReadOnlyContext, InternalKeyedBroadcastProcessFunctionContext, InternalKeyedBroadcastProcessFunctionReadOnlyContext, InternalKeyedBroadcastProcessFunctionOnTimerContext
  from pyflink.fn_execution.datastream.process.timerservice_impl import TimerServiceImpl, InternalTimerServiceImpl, NonKeyedTimerServiceImpl
  from pyflink.fn_execution.datastream.window.window_operator import WindowOperator
  from pyflink.fn_execution.metrics.process.metric_impl import GenericMetricGroup
label_desc: Use image node_id 1 to create a new StatelessOperation object from inherited base classes: Operation with example: obj = StatelessOperation(serialized_fn, operator_state_backend)