    @Test
    public void testReplaceParam()
    {

        HttpRequest mockRequest = mock(HttpRequest.class);
        RewritePolicy mockPolicy = mock(RewritePolicy.class);
        when(mockPolicy.rewritten(URI.create("http://example.com/test?xyz=987&abc=123"), mockRequest)).thenReturn(URI.create("https://example.org/result"));

        // test that it returns whatever the delegate returns
        assertEquals(URI.create("https://example.org/result"),
                new Parametrizing(mockPolicy, TEST_PARAM.parameter("123")).rewritten(URI.create("http://example.com/test?abc=456&xyz=987"), mockRequest));
    }