### Question:
StringUtils { public static String createUnquotedString(String str) { if (isEmpty(str)) { return str; } if (str.startsWith("\"")) { str = str.substring(1); } if (str.endsWith("\"")) { str = str.substring(0, str.length() - 1); } return str; } private  StringUtils(); static boolean isEmpty(final String s); static boolean nonEmpty(final String s); static boolean hasNonEmpty(final String... values); static boolean isQuoted(String str); static String createQuotedString(final String str); static String createQuotedStringIfNotNumeric(String str); static String replaceIllegalCharsAttribute(final String value); static String replaceIllegalCharsForDataObjects(final String value); static String revertIllegalCharsAttribute(final String value); static String createUnquotedString(String str);  }### Answer:
@Test public void testCreateUnquotedConstantNull() { assertNull(StringUtils.createUnquotedString(null)); }
@Test public void testCreateUnquotedConstantEmpty() { assertEquals("", StringUtils.createUnquotedString("")); }
@Test public void testCreateUnquotedConstantNoAction() { assertEquals("-123", StringUtils.createUnquotedString("-123")); }
@Test public void testCreateUnquotedConstant() { assertEquals(" abc ", StringUtils.createUnquotedString("\" abc \"")); }