class_docstr: Pattern for a mutable list-like object shareable via a shared
  memory block.  It differs from the built-in list type in that these
  lists can not change their overall length (i.e. no append, insert,
  etc.)
  
  Because values are packed into a memoryview as bytes, the struct
  packing format for any storable value must require no more than 8
  characters to describe its format.
docstr: Used in concert with _back_transforms_mapping to convert values
  into the appropriate Python objects when retrieving them from
  the list as well as when storing them.
code: def _extract_recreation_code(value):
      """Used in concert with _back_transforms_mapping to convert values
      into the appropriate Python objects when retrieving them from
      the list as well as when storing them."""
      if not isinstance(value, (str, bytes, None.__class__)):
          return 0
      elif isinstance(value, str):
          return 1
      elif isinstance(value, bytes):
          return 2
      else:
          return 3
  
imports: from functools import partial
  import mmap
  import os
  import errno
  import struct
  import secrets
  import types
label_desc: Use image node_id 1 for calling the ShareableList obj's underlying member method code with example usage: obj._extract_recreation_code(value) and returns: int, int, int, int