code: def _open(self):
      if self.shm_name and not self.memory:
          self.memory = shm.SharedMemory(name=self.shm_name)
      return self.memory
  
file_path: lkpy/lenskit/sharing/shm.py
imports: import sys
  import logging
  import pickle
  from .None import sharing_mode, PersistedModel
  import multiprocessing.shared_memory
label_desc: Use image node_id 4 for calling the SHMPersisted obj's underlying member method code with example usage: obj._open() and returns: self