code: def evict_tensors(
      self, can_evict_chunks: List[Chunk], **kwargs
  ) -> Tuple[int, float]:
      raise NotImplementedError
  
imports: import functools
  import warnings
  from abc import ABC, abstractmethod
  from time import time
  from typing import Dict, List, Optional, Tuple, Type
  import torch
  from colossalai.utils import get_current_device
  from colossalai.utils.memory import colo_device_memory_capacity
  from colossalai.zero.gemini.chunk import Chunk
  from .chunk import Chunk, ChunkManager
  from .memory_tracer import ChunkMemStatsCollector
label_desc: Use image node_id 2 for calling the PlacementPolicy obj's underlying member method code with example usage: obj.evict_tensors(can_evict_chunks) without return types