### Question:
Lz4Util { public static byte[] compress(byte[] bytes) { if (bytes == null) { throw new NullPointerException("bytes is null"); } LZ4Compressor compressor = LZ4Factory.fastestInstance().fastCompressor(); ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); try (LZ4BlockOutputStream lz4BlockOutputStream = new LZ4BlockOutputStream(outputStream, ARRAY_SIZE, compressor)) { lz4BlockOutputStream.write(bytes); } catch (IOException e) { LOGGER.error("compress bytes error", e); } return outputStream.toByteArray(); }  static byte[] compress(byte[] bytes); static byte[] decompress(byte[] bytes);  }### Answer:
@Test public void testCompress() { Assertions.assertThrows(NullPointerException.class, () -> { Lz4Util.compress(null); }); }