def testLpxErase(self):
lp = LPX()
lp.cols.add(2)
lp.rows.add(2)
self.assertEqual(len(lp.cols), 2)
self.assertEqual(len(lp.rows), 2)
lp.erase()
self.assertEqual(len(lp.cols), 0)
self.assertEqual(len(lp.rows), 0)
