### Question:
NmeaUtil { static boolean isValidCharacterSymbol(char ch) { return validCharacterSymbols.contains(ch); } private  NmeaUtil(); static boolean isValid(String sentence); static String getChecksum(String sentence); static String getChecksum(String sentence, boolean ignoreLeadingDollarOrExclamation); static NmeaMessage parseNmea(String line); static String insertKeyValueInTagBlock(String line, String name, String value); static String supplementWithTime(String line, long arrivalTime); static Talker getTalker(String s); static String createTagBlock(LinkedHashMap<String, String> tags); static String createNmeaLine(LinkedHashMap<String, String> tags, List<String> items);  }### Answer:
@Test public void testValidCharacterSymbol() { assertTrue(NmeaUtil.isValidCharacterSymbol('A')); assertTrue(NmeaUtil.isValidCharacterSymbol('a')); assertTrue(NmeaUtil.isValidCharacterSymbol('B')); assertFalse(NmeaUtil.isValidCharacterSymbol('b')); }