text: import pytest
  
  import pandas as pd
  
  import message_ix.utils as utils
  import pandas.util.testing as pdt
  
  
  def test_make_df():
      base = {'foo': 'bar'}
      exp = pd.DataFrame({'foo': 'bar', 'baz': [42, 42]})
      obs = utils.make_df(base, baz=[42, 42])
      pdt.assert_frame_equal(obs, exp)
  
  
  def test_make_df_raises():
      pytest.raises(ValueError, utils.make_df, 42, baz=[42, 42])
  