### Question:
StringUtils { public static boolean isCharEqual(char[] str) { char c0 = str[0]; for (char c : str) { if (c != c0) { return false; } } return true; }  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 isCharEqual() { char[] a = "aaaaaa".toCharArray(); char[] b = "aaaaab".toCharArray(); Assert.assertTrue(StringUtils.isCharEqual(a)); Assert.assertFalse(StringUtils.isCharEqual(b)); }