class_docstr: A simple PUBHandler subclass that sets root_topic
class_docstr_tok: ["A","simple","PUBHandler","subclass","that","sets","root_topic"]
docstr: this is a property, in case the handler is created
  before the engine gets registered with an id
docstr_tok: ["this","is","a","property",",","in","case","the","handler","is","created","before","the","engine","gets","registered","with","an","id"]
code: def root_topic(self):
      """this is a property, in case the handler is created
      before the engine gets registered with an id"""
      if isinstance(getattr(self.engine, "id", None), int):
          return "engine.%i" % self.engine.id  # type:ignore[union-attr]
      return "engine"
  
imports: import warnings
  from zmq.log.handlers import PUBHandler
label_desc: Use image node_id 2 for calling the EnginePUBHandler obj's underlying member method code with example usage: obj.root_topic() and returns: str, unknown