code: def process(
      self,
      key: str,
      context: ProcessWindowFunction.Context[TimeWindow],
      elements: Iterable[tuple],
  ) -> Iterable[tuple]:
      return [
          (
              key,
              context.window().start,
              context.window().end,
              len([e for e in elements]),
          )
      ]
  
file_path: flink/flink-python/pyflink/examples/datastream/windowing/tumbling_time_window.py
imports: import sys
  import argparse
  from typing import Iterable
  from pyflink.datastream.connectors.file_system import FileSink, OutputFileConfig, RollingPolicy
  from pyflink.common import Types, WatermarkStrategy, Time, Encoder
  from pyflink.common.watermark_strategy import TimestampAssigner
  from pyflink.datastream import StreamExecutionEnvironment, ProcessWindowFunction
  from pyflink.datastream.window import TumblingEventTimeWindows, TimeWindow
label_desc: Use image node_id 1 for calling the CountWindowProcessFunction obj's underlying member method code with example usage: obj.process(key, context, elements) and returns: list