class_docstr: The implementation of InternalWindowProcessFunction for MergingWindowAssigner.
class_docstr_tok: ["The","implementation","of","InternalWindowProcessFunction","for","MergingWindowAssigner","."]
code: def __init__(
      self,
      allowed_lateness: int,
      window_assigner: MergingWindowAssigner[W],
      window_aggregator,
      state_backend,
  ):
      super(MergingWindowProcessFunction, self).__init__(
          allowed_lateness, window_assigner, window_aggregator
      )
      self._window_assigner = window_assigner
      self._reuse_actual_windows = None  # type: List
      self._window_mapping = None  # type: MapState
      self._state_backend = state_backend
      self._sorted_windows = None  # type: List
  
      from pyflink.fn_execution.state_impl import LRUCache
  
      self._cached_sorted_windows = LRUCache(10000, 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 MergingWindowProcessFunction object from inherited base classes: InternalWindowProcessFunction with example: obj = MergingWindowProcessFunction(allowed_lateness, window_assigner, window_aggregator, state_backend)