### Question:
DdlVersionDirectoryTreeImpl implements DdlVersionDirectoryTree { public DdlVersionDirectory getNextVersionDirectory() { return createDdlVersionDirectory(ddlInfoFile.getNextVersionNo()); } DdlVersionDirectoryTreeImpl(File baseDir, File versionFile,
            String versionNoPattern, String env); DdlVersionDirectory getCurrentVersionDirectory(); DdlVersionDirectory getNextVersionDirectory(); DdlVersionDirectory getVersionDirectory(int versionNo); DdlInfoFile getDdlInfoFile();  }### Answer:
@Test public void testGetNextVersionDir() { File dir = tree.getNextVersionDirectory().asFile(); assertEquals("aaa", dir.getParentFile().getName()); assertEquals("0001", dir.getName()); }