code: def test_channel_builder(self):
      class CustomChannelBuilder(ChannelBuilder):
          @property
          def userId(self) -> Optional[str]:
              return "abc"
  
      client = SparkConnectClient(
          CustomChannelBuilder("sc://foo/"),
          use_reattachable_execute=False,
      )
  
      self.assertEqual(client._user_id, "abc")
  
imports: import unittest
  import uuid
  from collections.abc import Generator
  from typing import Optional, Any
  from pyspark.testing.connectutils import should_test_connect, connect_requirement_message
  from pyspark.testing.utils import eventually
label_desc: Use image node_id 4 for calling the SparkConnectClientTestCase obj's underlying member method code with example usage: obj.test_channel_builder() and returns: str