code: def _extract_conn_config(self, custom_config):
      unpacked_custom_config = example_gen_pb2.CustomConfig()
      proto_utils.json_to_proto(custom_config, unpacked_custom_config)
  
      conn_config = presto_config_pb2.PrestoConnConfig()
      unpacked_custom_config.custom_config.Unpack(conn_config)
      return conn_config
  
file_path: tfx/tfx/examples/custom_components/presto_example_gen/presto_component/component_test.py
imports: import tensorflow
  from tfx.examples.custom_components.presto_example_gen.presto_component import component
  from tfx.examples.custom_components.presto_example_gen.proto import presto_config_pb2
  from tfx.proto import example_gen_pb2
  from tfx.types import standard_artifacts
  from tfx.utils import proto_utils
label_desc: Use image node_id 2 for calling the ComponentTest obj's underlying member method code with example usage: obj._extract_conn_config(custom_config) and returns: conn_config