class_docstr: These test cases exercise the interface to the proto plan
  generation but do not call Spark.
code: def setUpClass(cls):
      super(SparkConnectMLFunctionTests, cls).setUpClass()
      # Disable the shared namespace so pyspark.sql.functions, etc point the regular
      # PySpark libraries.
      os.environ["PYSPARK_NO_NAMESPACE_SHARE"] = "1"
      cls.connect = (
          cls.spark
      )  # Switch Spark Connect session and regular PySpark sesion.
      cls.spark = PySparkSession._instantiatedSession
      assert cls.spark is not None
  
file_path: spark/python/pyspark/ml/tests/connect/test_connect_function.py
imports: import os
  import unittest
  from pyspark.sql import SparkSession
  from pyspark.sql.dataframe import DataFrame
  from pyspark.ml import functions
  from pyspark.testing.sqlutils import SQLTestUtils
  from pyspark.testing.connectutils import should_test_connect, ReusedConnectTestCase
  from pyspark.testing.pandasutils import PandasOnSparkTestUtils
label_desc: Use image node_id 1 for calling the SparkConnectMLFunctionTests obj's underlying member method code with example usage: obj.setUpClass(cls) without return types