class_docstr: Internal implementation of TimerService for ProcessFunction and CoProcessFunction.
code: def register_event_time_timer(self, t: int):
      raise Exception(
          "Register timers is only supported on a keyed stream."
      )
  
imports: import collections
  import time
  from enum import Enum
  from io import BytesIO
  from pyflink.common import Row
  from pyflink.datastream import TimerService
  from pyflink.fn_execution.datastream.timerservice import InternalTimer, K, N, InternalTimerService
label_desc: Use image node_id 6 for calling the NonKeyedTimerServiceImpl obj's underlying member method code with example usage: obj.register_event_time_timer(t) without return types