code: def process(self, query):
      yield {
          ("i", "integer", 1),
          ("f", "double", 2.0),
          ("s", "varchar", "abc"),
      }
  
imports: import os
  import random
  from unittest import mock
  import apache_beam
  from apache_beam.testing import util
  import prestodb
  import tensorflow
  from tfx.dsl.io import fileio
  from tfx.examples.custom_components.presto_example_gen.presto_component import executor
  from tfx.examples.custom_components.presto_example_gen.proto import presto_config_pb2
  from tfx.proto import example_gen_pb2
  from tfx.types import artifact_utils
  from tfx.types import standard_artifacts
  from tfx.utils import proto_utils
label_desc: Use image node_id 2 for calling the _MockReadPrestoDoFn2 obj's underlying member method code with example usage: obj.process(query) without return types