### Question:
Version implements Comparable<Version> { public int compareTo(Version o) { return items.compareTo(o.items); } Version(String version); boolean satisfies(String expr); int compareTo(Version o); String toString(); boolean equals(Object o); int hashCode(); boolean greaterThan(Version other); boolean greaterThanOrEqualTo(Version other); boolean lessThan(Version other); boolean lessThanOrEqualTo(Version other);  }### Answer:
@Test public void testCompareVersionEquals() throws Exception { { Version version1 = new Version("27.0.0"); Version version2 = new Version("27.0.0"); Assert.assertTrue(version1.compareTo(version2) == 0); } { Version version1 = new Version("27.0"); Version version2 = new Version("27.0.0"); Assert.assertTrue(version1.compareTo(version2) == 0); } { Version version1 = new Version("27"); Version version2 = new Version("27.0.0"); Assert.assertTrue(version1.compareTo(version2) == 0); } { Version version1 = new Version("27"); Version version2 = new Version("27.0"); Assert.assertTrue(version1.compareTo(version2) == 0); } { Version version1 = new Version("27.0"); Version version2 = new Version("27.0.0"); Assert.assertTrue(version1.compareTo(version2) == 0); } }
@Test public void testCompareVersionGreater() throws Exception { { Version version1 = new Version("27.0.0"); Version version2 = new Version("26.0.0"); Assert.assertTrue(version1.compareTo(version2) > 0); } { Version version1 = new Version("26.0.1"); Version version2 = new Version("26.0.0"); Assert.assertTrue(version1.compareTo(version2) > 0); } { Version version1 = new Version("26.0.1"); Version version2 = new Version("26.0"); Assert.assertTrue(version1.compareTo(version2) > 0); } { Version version1 = new Version("26.0.1"); Version version2 = new Version("26"); Assert.assertTrue(version1.compareTo(version2) > 0); } { Version version1 = new Version("26.1"); Version version2 = new Version("26"); Assert.assertTrue(version1.compareTo(version2) > 0); } { Version version1 = new Version("20171218"); Version version2 = new Version("20171018"); Assert.assertTrue(version1.compareTo(version2) > 0); } }