class_docstr: The implementation of InternalWindowProcessFunction for MergingWindowAssigner.
class_docstr_tok: ["The","implementation","of","InternalWindowProcessFunction","for","MergingWindowAssigner","."]
code: def assign_actual_windows(
      self, input_row: List, timestamp: int
  ) -> List[W]:
      # the actual windows is calculated in assignStateNamespace
      return self._reuse_actual_windows
  
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 4 for calling the MergingWindowProcessFunction obj's underlying member method code with example usage: obj.assign_actual_windows(input_row, timestamp) and returns: self