code: def token_bytes(nbytes=None):
      """Return a random byte string containing *nbytes* bytes.
  
      If *nbytes* is ``None`` or not supplied, a reasonable
      default is used.
  
      >>> token_bytes(16)  #doctest:+SKIP
      b'\\xebr\\x17D*t\\xae\\xd4\\xe3S\\xb6\\xe2\\xebP1\\x8b'
  
      """
      if nbytes is None:
          nbytes = DEFAULT_ENTROPY
      return _sysrand.randbytes(nbytes)
  
file_path: catboost/contrib/tools/python3/src/Lib/secrets.py
imports: import base64
  import binascii
  from hmac import compare_digest
  from random import SystemRandom
label_desc: Use image node_id 2 for calling a global function with example usage: token_bytes(nbytes) and returns: _sysrand