code: def _get_backing_memmap(a):
      """Recursively look up the original np.memmap instance base if any."""
      b = getattr(a, "base", None)
      if b is None:
          # TODO: check scipy sparse datastructure if scipy is installed
          # a nor its descendants do not have a memmap base
          return None
  
      elif isinstance(b, mmap):
          # a is already a real memmap instance.
          return a
  
      else:
          # Recursive exploration of the base ancestry
          return _get_backing_memmap(b)
  
imports: from mmap import mmap
  import errno
  import os
  import stat
  import sys
  import threading
  import atexit
  import tempfile
  import shutil
  import warnings
  from time import sleep
  from pickle import whichmodule
  from pickle import Pickler
  from pickle import HIGHEST_PROTOCOL
  from io import BytesIO
  from ._multiprocessing_helpers import mp, assert_spawning
  from multiprocessing.pool import Pool
  from .numpy_pickle import load
  from .numpy_pickle import dump
  from .hashing import hash
  from .backports import make_memmap
label_desc: Use image node_id 1 for calling a global function with example usage: _get_backing_memmap(a) and returns: None, a, _get_backing_memmap