code: def hash_function(fn, callback_id=""):
      fn_source = inspect.getsource(fn)
      fn_str = fn_source
      return hashlib.sha1(
          callback_id.encode("utf-8") + fn_str.encode("utf-8")
      ).hexdigest()
  
file_path: dash/dash/long_callback/managers/__init__.py
imports: from abc import ABC
  import inspect
  import hashlib
label_desc: Use image node_id 14 for calling the BaseLongCallbackManager obj's underlying member method code with example usage: obj.hash_function(fn, callback_id) and returns: hashlib