new_contents: # ----------------------------------------------------------------------------
  # Copyright (c) 2017--,  Calour development team.
  #
  # Distributed under the terms of the Modified BSD License.
  #
  # The full license is in the file COPYING.txt, distributed with this software.
  # ----------------------------------------------------------------------------
  
  from unittest import main, TestCase
  
  import numpy as np
  import pandas as pd
  from numpy.testing import assert_array_almost_equal
  
  from calour import Experiment
  
  
  class PlotTests(TestCase):
      def test_plot_hist(self):
          exp = Experiment(np.array([[0, 1], [2, 3]]),
                           pd.DataFrame({'A': ['ab', 'cd'], 'B': ['ef', 'gh']}))
          counts, bins, fig = exp.plot_hist(bins=4)
          assert_array_almost_equal(counts, np.array([1] * 4))
          assert_array_almost_equal(bins, np.array([0., 0.75, 1.5, 2.25, 3.]))
          ax = fig.gca()
          # test the numbers on top of the histogram bars are correct
          self.assertEqual([i.get_text() for i in ax.texts], ['1'] * 4)
  
  
  if __name__ == '__main__':
      main()
  
subject: add test for plotting module