def test_unit_cell_updates_distributions(self):
        generator = BraggPeakEventGenerator(['5.431 5.431 5.431', 'F d -3 m', 'Si 0 0 0 1.0 0.01'], 3.0, 4.0,
                                            MockTOFFactorCalculator([2500.]))

        with patch.object(generator, '_update_distributions_and_weights') as mock_method:
            generator.unit_cell = '4 4 4'
            self.assertEquals(generator.unit_cell, '4 4 4')

        self.assertEqual(mock_method.call_count, 1,
                         '_update_distributions_and_weights has been called the wrong number of times when setting unit_cell: {}'.format(
                             mock_method.call_count))