class_docstr: implementation of server-side SCRAM-SHA-1 and SCRAM-SHA-256 auth for mongodb
      
code: def _hmac(self, key, msg):
      return hmac.new(key, msg, digestmod=self.method_func).digest()
  
file_path: mindsdb/mindsdb/api/mongo/classes/scram.py
imports: import base64
  import hashlib
  import hmac
  import os
  from pymongo.auth import _password_digest, _xor, saslprep
label_desc: Use image node_id 4 for calling the Scram obj's underlying member method code with example usage: obj._hmac(key, msg) and returns: hmac