code: def add(self, namespace, pass_func):
      func_name = pass_func.__name__
      pass_id = namespace + "::" + func_name
      logging.debug("Registering pass {}".format(pass_id))
      if pass_id in self.passes:
          msg = "Pass {} already registered."
          raise KeyError(msg.format(pass_id))
      self.passes[pass_id] = pass_func
  
imports: import logging
label_desc: Use image node_id 3 for calling the PassRegistry obj's underlying member method code with example usage: obj.add(namespace, pass_func) without return types