code: def get_test_data(backend: str) -> Tuple[DataFrame, DataFrame]:
      """Returns test data for the given backend."""
      data_df = pd.DataFrame(pd.Series([2, 4, 6, 8, 10]), columns=["x"])
      proc_df = pd.DataFrame(columns=["x"])
      if backend == "ray":
          import dask.dataframe as dd
  
          data_df = dd.from_pandas(data_df, npartitions=1).reset_index()
          proc_df = dd.from_pandas(proc_df, npartitions=1).reset_index()
      return data_df, proc_df
  
file_path: ludwig/tests/ludwig/utils/test_normalization.py
imports: from typing import Tuple
  import numpy
  import pandas
  import pytest
  from ludwig.backend import initialize_backend
  from ludwig.constants import COLUMN, NAME, PROC_COLUMN
  from ludwig.features.feature_utils import compute_feature_hash
  from ludwig.features.number_feature import NumberFeatureMixin, numeric_transformation_registry
  from ludwig.utils.types import DataFrame
label_desc: Use image node_id 2 for calling a global function with example usage: get_test_data(backend) and returns: data_df,  proc_df