class TestAbstractChart(TestCase):
    def setUp(self):
        self.abstract_plot = AbstractPlot()
        self.path = "/tmp/abstract.png"

    def test_resolution(self):
        self.assertEqual(self.abstract_plot.get_resolution(), Resolution(800, 600))

    def test_save(self):
        self.abstract_plot.save_as_png(self.path)
        self.assertTrue(os.path.isfile(self.path))
        os.remove(self.path)
 def setUp(self):
     self.abstract_plot = AbstractPlot()
     self.path = "/tmp/abstract.png"