### Question:
StrUtils { public static boolean isCodeOk(String code) { Matcher m = codePattern.matcher(code); return m.matches(); }  static boolean isCodeOk(String code); static String normalizeCode(String code); @Nullable static String getExtension(String filename); static String getName(File file); static String getName(String filename); static String incCopyNumber(String s); static final String ALLOWED_CHARS_IN_CODE_REGEXP; }### Answer:
@Test public void testMatching() { assertTrue(StrUtils.isCodeOk("1234567890-abc_xyz:1.0")); assertTrue(StrUtils.isCodeOk("aaa.txt")); assertTrue(StrUtils.isCodeOk("aaa.")); assertFalse(StrUtils.isCodeOk("1234567890-?#$%abc_xyz:1.0")); assertFalse(StrUtils.isCodeOk("aaa bbb.txt")); assertFalse(StrUtils.isCodeOk("aaa,bbb.txt")); assertFalse(StrUtils.isCodeOk("aaaäöü.txt")); }