code: def __contains__(self, key):
      return os.path.isfile(self._path(key))
  
imports: import os
  import gc
  import pickle
  import lore
  from lore.stores.base import Base
  from lore.util import timer
  from lore.env import require
  import pandas
  from datetime import datetime
label_desc: Use image node_id 5 for calling the Disk obj's underlying member method code with example usage: obj.__contains__(key) and returns: os