def test_change_direction(self):
        self.obj.direction = "min"
        self.assertEqual(self.obj.direction, "min")
        self.assertEqual(glpk_interface.glp_get_obj_dir(self.model.problem), glpk_interface.GLP_MIN)

        self.obj.direction = "max"
        self.assertEqual(self.obj.direction, "max")
        self.assertEqual(glpk_interface.glp_get_obj_dir(self.model.problem), glpk_interface.GLP_MAX)
    def test_change_direction(self):
        self.obj.direction = "min"
        self.assertEqual(self.obj.direction, "min")
        self.assertEqual(glpk_interface.glp_get_obj_dir(self.model.problem),
                         glpk_interface.GLP_MIN)

        self.obj.direction = "max"
        self.assertEqual(self.obj.direction, "max")
        self.assertEqual(glpk_interface.glp_get_obj_dir(self.model.problem),
                         glpk_interface.GLP_MAX)