@Override
    public Object getValue(Object elContext) {
        return expression.getValue(elContext);
    }
@Test
    public void testGetValue() {
        ExpressionParser parser = new SpelExpressionParser();
        Expression defaultExpression = parser.parseExpression("'Hello World'.concat('!')");
        String value = (String) new SpringELExpression(defaultExpression).getValue(null);
        Assertions.assertEquals(value, "Hello World!");
    }