### Question:
JpqlFunctionUtil { public static String unquoteSingleQuotes(String s) { return unquote(s, '\''); } private  JpqlFunctionUtil(); static String unquoteSingleQuotes(String s); static String unquoteDoubleQuotes(String s);  }### Answer:
@Test public void testUnquoteSingleQuotes() { assertEquals("0", JpqlFunctionUtil.unquoteSingleQuotes("0")); assertEquals("0", JpqlFunctionUtil.unquoteSingleQuotes("'0'")); assertEquals("'0'", JpqlFunctionUtil.unquoteSingleQuotes("''0''")); }