### Question:
DataNodeLayoutVersion { private DataNodeLayoutVersion(int version, String description) { this.description = description; this.version = version; } private  DataNodeLayoutVersion(int version, String description); static DataNodeLayoutVersion[] getAllVersions(); static DataNodeLayoutVersion getLatestVersion(); String getDescription(); int getVersion();  }### Answer:
@Test public void testDatanodeLayOutVersion() { Assert.assertEquals(1, DataNodeLayoutVersion.getLatestVersion() .getVersion()); Assert.assertEquals("HDDS Datanode LayOut Version 1", DataNodeLayoutVersion .getLatestVersion().getDescription()); Assert.assertEquals(DataNodeLayoutVersion.getAllVersions().length, DataNodeLayoutVersion.getAllVersions().length); }