### Question:
Utils { public static String bytesToHex(byte[] bytes) { return HashCode.fromBytes(bytes).toString().toUpperCase(); }  static DateTime receiverTimeToDateTime(long deltaInSeconds); static Date receiverTimeToDate(long delta); static String getTimeAgoString(Period period); static String getTimeString(long timeDeltaMS); static List<GlucoseDataSet> mergeGlucoseDataRecords(List<SensorGlucoseValueEntry> egvRecords,
                                                               List<SensorEntry> sensorRecords); static String bytesToHex(byte[] bytes); static final DateTime DEXCOM_EPOCH; }### Answer:
@Test public void testBytesToHex_Simple() { assertThat(Utils.bytesToHex(new byte[]{0xA}), is("0A")); }
@Test public void testBytesToHex_Multiple() { assertThat(Utils.bytesToHex(new byte[]{ UnsignedBytes.checkedCast(0xDE), UnsignedBytes.checkedCast(0xAD), UnsignedBytes.checkedCast(0xBE), UnsignedBytes.checkedCast(0xEF)}), is("DEADBEEF")); }