### Question:
SegmentDirectoryPaths { public static File segmentDirectoryFor(File indexDir, SegmentVersion segmentVersion) { switch (segmentVersion) { case v1: case v2: return indexDir; case v3: return new File(indexDir, V3_SUBDIRECTORY_NAME); default: throw new UnsupportedOperationException( "Unsupported segment version: " + segmentVersion + " while trying to get segment directory from: " + indexDir); } } private  SegmentDirectoryPaths(); static File segmentDirectoryFor(File indexDir, SegmentVersion segmentVersion); static File findSegmentDirectory(File indexDir); static boolean isV3Directory(File path); @Nullable static File findMetadataFile(File indexDir); @Nullable static File findCreationMetaFile(File indexDir); @Nullable static File findTextIndexIndexFile(File indexDir, String column); @Nullable @VisibleForTesting static File findTextIndexDocIdMappingFile(File indexDir, String column); static final String V3_SUBDIRECTORY_NAME; }### Answer:
@Test public void testSegmentDirectoryFor() { File f = new File("f"); File v1Dir = SegmentDirectoryPaths.segmentDirectoryFor(f, SegmentVersion.v1); File v2Dir = SegmentDirectoryPaths.segmentDirectoryFor(f, SegmentVersion.v2); File v3Dir = SegmentDirectoryPaths.segmentDirectoryFor(f, SegmentVersion.v3); Assert.assertEquals(v1Dir, f); Assert.assertEquals(v2Dir, f); Assert.assertEquals(v3Dir, new File("f", SegmentDirectoryPaths.V3_SUBDIRECTORY_NAME)); }