@Test
 public void testComparability1() {
   PythonVersion v12 = new PythonVersion(1, 2, "");
   PythonVersion v21 = new PythonVersion(2, 1, "");
   int z = v12.compareTo(v21);
   assertTrue(z < 0);
 }
 @Test
 public void testComparability2() {
   PythonVersion v26 = new PythonVersion(2, 6, "");
   PythonVersion v27 = new PythonVersion(2, 7, "");
   int z = v26.compareTo(v27);
   assertTrue(z < 0);
 }
 @Test
 public void testComparability3() {
   PythonVersion v331 = new PythonVersion(3, 3, "3.3.1");
   PythonVersion v333 = new PythonVersion(3, 3, "3.3.3");
   int z = v331.compareTo(v333);
   assertTrue(z < 0);
   assertFalse(v331.equals(v333));
 }