code: def write_file(self):
          
          name = "kernel-{pid}.json".format(pid=os.getpid())
          path = os.path.join(jupyter_runtime_dir(), name)
  
          # indentation, because why not.
          connection_json = json.dumps(self.connection_props, indent=2)
  
          with open(path, "w") as connection_file:
              connection_file.write(connection_json)
          
          return path
docs: Write a new connection file to disk. and
          return its path