code: def test_should_raise_or_replace_if_not_exists(self):
      plan = type(
          "CreateFunctionPlan",
          (),
          {
              "name": "function",
              "or_replace": True,
              "if_not_exists": True,
          },
      )
      evadb = MagicMock()
      create_function_executor = CreateFunctionExecutor(evadb, plan)
      with self.assertRaises(AssertionError) as cm:
          next(create_function_executor.exec())
      self.assertEqual(
          str(cm.exception),
          "OR REPLACE and IF NOT EXISTS can not be both set for CREATE FUNCTION.",
      )
  
file_path: evadb/test/unit_tests/executor/test_create_udf_executor.py
imports: import unittest
  from mock import MagicMock, patch
  from evadb.catalog.catalog_type import NdArrayType
  from evadb.executor.create_function_executor import CreateFunctionExecutor
  from evadb.functions.decorators.io_descriptors.data_types import PandasDataframe
label_desc: Use image node_id 2 for calling the CreateFunctionExecutorTest obj's underlying member method code with example usage: obj.test_should_raise_or_replace_if_not_exists() without return types