code: def _hash_sha1(buf):
      """
      Produce a 20-bytes hash of *buf* using SHA1.
      """
      return hashlib.sha1(buf).digest()
  
imports: from __future__ import annotations
  import binascii
  import hashlib
label_desc: Use image node_id 1 for calling a global function with example usage: _hash_sha1(buf) and returns: hashlib