### Question:
StringUtils { public static void clear(char[] a) { if (ArrayUtils.isEmpty(a)) { return; } for (int i = 0; i < a.length; i++) { a[i] = 0; } }  static boolean isCharEqual(char[] str); static boolean isNumeric(char[] str); static boolean isContains(char[] a, char[] b); static void clear(char[] a); static void clear(byte[] a); static byte[] char2Byte(char[] a); static char[] byte2Char(byte[] a); static void printOneByte(byte b); static byte[] hexs2Bytes(byte[] a);  }### Answer:
@Test public void clear() { byte[] chars1 = "test".getBytes(); byte[] chars2 = new byte[chars1.length]; StringUtils.clear(chars1); Assert.assertArrayEquals(chars1, chars2); }
@Test public void clear1() { char[] chars1 = "test".toCharArray(); char[] chars2 = new char[chars1.length]; StringUtils.clear(chars1); Assert.assertArrayEquals(chars1, chars2); }