### Question:
RomanNumberConverter { public static boolean isRomanNumber(String str) { return str.matches("(?:([MDCLXVI])(?!\\1{3,}))+"); }  static int decode(String roman); static boolean isRomanNumber(String str); static boolean isNotRomanNumber(String str);  }### Answer:
@Test @UseDataProvider("simpleStringData") public void isRomanNumber_simple_string_with_roman_number(String romanNumber) { assertTrue(RomanNumberConverter.isRomanNumber(romanNumber)); }
@Test @UseDataProvider("incorrectStringData") public void isRomanNumber_incorrect_string(String romanNumber) { assertFalse(RomanNumberConverter.isRomanNumber(romanNumber)); }