code: def predict(self, context, model_input):
      return [
          str(" | ".join(map(str, row)))
          for _, row in model_input.iterrows()
      ]
  
imports: from pyspark.sql import SparkSession
  from pyspark.sql import types
  import mlflow
label_desc: Use image node_id 1 for calling the MyModel obj's underlying member method code with example usage: obj.predict(context, model_input) and returns: unknown