@Test
 public void setContentType() {
   String contentType = "test/plain";
   response.setContentType(contentType);
   assertEquals(contentType, response.getContentType());
   assertEquals(contentType, response.getHeader("Content-Type"));
   assertEquals(WebUtils.DEFAULT_CHARACTER_ENCODING, response.getCharacterEncoding());
 }
 @Test
 public void setContentTypeUTF8() {
   String contentType = "test/plain;charset=UTF-8";
   response.setContentType(contentType);
   assertEquals("UTF-8", response.getCharacterEncoding());
   assertEquals(contentType, response.getContentType());
   assertEquals(contentType, response.getHeader("Content-Type"));
 }
 @Test
 public void setCharacterEncodingThenContentType() {
   response.setCharacterEncoding("UTF-8");
   response.setContentType("test/plain");
   assertEquals("test/plain", response.getContentType());
   assertEquals("test/plain;charset=UTF-8", response.getHeader("Content-Type"));
   assertEquals("UTF-8", response.getCharacterEncoding());
 }