class_docstr: The internal interface for functions that process over grouped windows.
class_docstr_tok: ["The","internal","interface","for","functions","that","process","over","grouped","windows","."]
code: def __init__(
      self,
      allowed_lateness: int,
      window_assigner: WindowAssigner[W],
      window_aggregator,
  ):
      self._allowed_lateness = allowed_lateness
      self._window_assigner = window_assigner
      self._window_aggregator = window_aggregator
      self._ctx = None
  
imports: from abc import abstractmethod, ABC
  from typing import Generic, List, Iterable, Dict, Set
  from pyflink.common import Row
  from pyflink.common.constants import MAX_LONG_VALUE
  from pyflink.datastream.state import MapState
  from pyflink.fn_execution.table.window_assigner import WindowAssigner, PanedWindowAssigner, MergingWindowAssigner
  from pyflink.fn_execution.table.window_context import Context, K, W
label_desc: Use image node_id 1 to create a new InternalWindowProcessFunction object from inherited base classes: Generic, ABC with example: obj = InternalWindowProcessFunction(allowed_lateness, window_assigner, window_aggregator)