### Question:
StrKit { public static String firstCharToUpperCase(String str) { char firstChar = str.charAt(0); if (firstChar >= 'a' && firstChar <= 'z') { char[] arr = str.toCharArray(); arr[0] -= ('a' - 'A'); return new String(arr); } return str; }  static String firstCharToLowerCase(String str); static String firstCharToUpperCase(String str); static boolean isEmpty(String str); static boolean isNotEmpty(String str); static String nullToEmpty(String str); static String nullToDefault(String str, String defaultStr); static String toUnderlineCase(String camelCaseStr); static String toCamelCase(String name); static final String SPACE; static final String DOT; static final String SLASH; static final String BACKSLASH; static final String EMPTY; static final String CRLF; static final String NEWLINE; static final String UNDERLINE; static final String COMMA; static final String HTML_NBSP; static final String HTML_AMP; static final String HTML_QUOTE; static final String HTML_LT; static final String HTML_GT; static final String EMPTY_JSON; }### Answer:
@Test public void testFirstCharToUpperCase() { Assert.assertEquals("BAZ", StrKit.firstCharToUpperCase("BAZ")); Assert.assertEquals("Foo", StrKit.firstCharToUpperCase("foo")); }