class_docstr: A message generated by an operator executed as a generator.
code: def to_json(self):
      return {
          "type": str(self.type),
          "cls": self.cls.__name__,
          "body": self.body.to_json() if self.body else None,
      }
  
file_path: fiftyone/fiftyone/operators/message.py
imports: from enum import Enum
  import json
label_desc: Use image node_id 2 for calling the GeneratedMessage obj's underlying member method code with example usage: obj.to_json() and returns: dict