code: def actor_cookie(self, actor):
      return self.ds.sign({"a": actor}, "actor")
  
file_path: datasette/datasette/utils/testing.py
imports: from asgiref.sync import async_to_sync
  from urllib.parse import urlencode
  import json
label_desc: Use image node_id 2 for calling the TestClient obj's underlying member method code with example usage: obj.actor_cookie(actor) and returns: self