public String toString() {
        return string;
    }
@Test
    public void testLowerCase() {
        assertEquals("text/plain", new MediaType("TEXT", "PLAIN").toString());
        assertEquals("text/plain", new MediaType("Text", "Plain").toString());

        Map<String, String> parameters = new HashMap<>();
        assertEquals("text/plain", new MediaType("text", "PLAIN", parameters).toString());

        parameters.put("CHARSET", "UTF-8");
        assertEquals("text/plain; charset=UTF-8",
                new MediaType("TEXT", "plain", parameters).toString());

        parameters.put("X-Eol-Style", "crlf");
        assertEquals("text/plain; charset=UTF-8; x-eol-style=crlf",
                new MediaType("TeXt", "PlAiN", parameters).toString());
    }