code: def predict(self, df, args=None):
      df["predicted"] = 42
      df["predictor_id"] = self.model_storage.predictor_id
      return df[["predicted", "predictor_id"]]
  
file_path: mindsdb/tests/unit/dummy_ml_handler/dummy_ml_handler.py
imports: import pandas
  from mindsdb.integrations.libs.base import BaseMLEngine
label_desc: Use image node_id 3 for calling the DummyHandler obj's underlying member method code with example usage: obj.predict(df, args) and returns: df