### Question:
CompressionUtil { public static boolean isFileExtensionSupported(String fileExt) { return (Algorithm.findByFileExtension(fileExt) != null); }  static boolean isAlgorithmSupported(String algorithm); static boolean isFileExtensionSupported(String fileExt); static File compress(File sourceFile, String algorithm, boolean deleteSourceFileAfterCompressed); static File compress(File sourceFile, File targetDir, String algorithm, boolean deleteSourceFileAfterCompressed); static File uncompress(File sourceFile, boolean deleteSourceFileAfterUncompressed); static File uncompress(File sourceFile, File targetDir, boolean deleteSourceFileAfterUncompressed);  }### Answer:
@Test public void isFileExtensionSupported() throws Exception { Assert.assertEquals(true, CompressionUtil.isFileExtensionSupported("gz")); Assert.assertEquals(true, CompressionUtil.isFileExtensionSupported("zip")); Assert.assertEquals(false, CompressionUtil.isFileExtensionSupported("txt")); Assert.assertEquals(false, CompressionUtil.isFileExtensionSupported("gz2")); }