class_docstr: Creates a new shared memory block or attaches to an existing
  shared memory block.
  
  Every shared memory block is assigned a unique name.  This enables
  one process to create a shared memory block with a particular name
  so that a different process can attach to that same shared memory
  block using that same name.
  
  As a resource for sharing data across processes, shared memory blocks
  may outlive the original process that created them.  When one process
  no longer needs access to a shared memory block that might still be
  needed by other processes, the close() method should be called.
  When a shared memory block is no longer needed by any process, the
  unlink() method should be called to ensure proper cleanup.
docstr: A memoryview of contents of the shared memory block.
docstr_tok: ["A","memoryview","of","contents","of","the","shared","memory","block","."]
code: def buf(self):
      "A memoryview of contents of the shared memory block."
      return self._buf
  
imports: from functools import partial
  import mmap
  import os
  import errno
  import struct
  import secrets
label_desc: Use image node_id 5 for calling the SharedMemory obj's underlying member method code with example usage: obj.buf() and returns: self