code: def free_seq(self, seq: Sequence) -> None:
      # bigdl-llm specified change
      # bigdl-llm change start
      # summary: The original code free the block in block_manager.
      # now, we added it into a list to pass to worker in the next model_execute stage.
      self.cleaned.append(seq.seq_id)
      for i in range(len(self.kv_cache)):
          for j in range(2):
              if not self.kv_cache[i][j].get(seq.seq_id) is None:
                  del self.kv_cache[i][j][seq.seq_id]
  
imports: import enum
  import time
  from typing import Dict, Iterable, List, Optional, Tuple, Union
  from bigdl.llm.vllm.config import SchedulerConfig
  from bigdl.llm.vllm.core.policy import PolicyFactory
  from bigdl.llm.vllm.logger import init_logger
  from bigdl.llm.vllm.sequence import SequenceData, SequenceStatus
  from bigdl.llm.vllm.sequence import Sequence, SequenceGroup, SequenceGroupMetadata
  from bigdl.llm.utils.common import invalidInputError
label_desc: Use image node_id 8 for calling the FixedWindowScheduler obj's underlying member method code with example usage: obj.free_seq(seq) without return types