code: def test_complement():
      (
          train_size,
          test_size,
      ) = dask_ml.model_selection._split._maybe_normalize_split_sizes(
          0.1, None
      )
      assert train_size == 0.1
      assert test_size == 0.9
  
      (
          train_size,
          test_size,
      ) = dask_ml.model_selection._split._maybe_normalize_split_sizes(
          None, 0.2
      )
      assert train_size == 0.8
      assert test_size == 0.2
  
imports: import dask.array
  import dask.dataframe
  import numpy
  import pandas
  import pytest
  from sklearn.datasets import fetch_20newsgroups, make_regression
  import dask_ml.model_selection
  from dask_ml._compat import DASK_2130
label_desc: Use image node_id 12 for calling a global function with example usage: test_complement() without return types