### Question:
BZip2Util { public static byte[] compress(byte[] bytes) { if (bytes == null) { throw new NullPointerException("bytes is null"); } ByteArrayOutputStream bos = new ByteArrayOutputStream(); try (CBZip2OutputStream bzip2 = new CBZip2OutputStream(bos)) { bzip2.write(bytes); bzip2.finish(); return bos.toByteArray(); } catch (IOException e) { throw new RuntimeException("BZip2 compress error", e); } }  static byte[] compress(byte[] bytes); static byte[] decompress(byte[] bytes);  }### Answer:
@Test public void test_compress() { Assertions.assertThrows(NullPointerException.class, () -> { BZip2Util.compress(null); }); }