code: def prepare_read(self, parallelism: int, **read_args):
      import pyarrow as pa
  
      def load_data():
          data_raw = load_breast_cancer(as_frame=True)
          dataset_df = data_raw["data"]
          dataset_df["target"] = data_raw["target"]
          return [pa.Table.from_pandas(dataset_df)]
  
      meta = BlockMetadata(
          num_rows=None,
          size_bytes=None,
          schema=None,
          input_files=None,
          exec_stats=None,
      )
      return [ReadTask(load_data, meta)]
  
file_path: ray/python/ray/tune/impl/test_utils.py
imports: from sklearn.datasets import load_breast_cancer
  from ray import tune
  from ray.data import read_datasource, Dataset, Datasource, ReadTask
  from ray.data.block import BlockMetadata
  from ray.tune.impl.utils import execute_dataset
label_desc: Use image node_id 1 for calling the TestDatasource obj's underlying member method code with example usage: obj.prepare_read(parallelism) and returns: list, list