code: def test_missing_required_keys(self):
      # create project
      self.run_sql("create database proj")
  
      self.run_sql(
          """
                  CREATE MODEL proj.test_rag_handler_missing_required_args
                  PREDICT answer
                  USING
                     engine="rag"
                     """
      )
      with pytest.raises(Exception):
          self.wait_predictor(
              "proj", "test_rag_handler_missing_required_args"
          )
  
file_path: mindsdb/tests/unit/ml_handlers/test_rag.py
imports: import os
  import time
  import pandas
  import pytest
  from mindsdb_sql import parse_sql
  from tests.unit.executor_test_base import BaseExecutorTest
label_desc: Use image node_id 3 for calling the TestRAG obj's underlying member method code with example usage: obj.test_missing_required_keys() without return types