### Question:
HttpUtil { public static CharSequence getCharsetAsSequence(HttpMessage message) { CharSequence contentTypeValue = message.headers().get(HttpHeaderNames.CONTENT_TYPE); if (contentTypeValue != null) { return getCharsetAsSequence(contentTypeValue); } else { return null; } } private  HttpUtil(); static boolean isOriginForm(URI uri); static boolean isAsteriskForm(URI uri); static boolean isKeepAlive(HttpMessage message); static void setKeepAlive(HttpMessage message, boolean keepAlive); static void setKeepAlive(HttpHeaders h, HttpVersion httpVersion, boolean keepAlive); static long getContentLength(HttpMessage message); static long getContentLength(HttpMessage message, long defaultValue); static int getContentLength(HttpMessage message, int defaultValue); static void setContentLength(HttpMessage message, long length); static boolean isContentLengthSet(HttpMessage m); static boolean is100ContinueExpected(HttpMessage message); static void set100ContinueExpected(HttpMessage message, boolean expected); static boolean isTransferEncodingChunked(HttpMessage message); static void setTransferEncodingChunked(HttpMessage m, boolean chunked); static Charset getCharset(HttpMessage message); static Charset getCharset(CharSequence contentTypeValue); static Charset getCharset(HttpMessage message, Charset defaultCharset); static Charset getCharset(CharSequence contentTypeValue, Charset defaultCharset); @Deprecated static CharSequence getCharsetAsString(HttpMessage message); static CharSequence getCharsetAsSequence(HttpMessage message); static CharSequence getCharsetAsSequence(CharSequence contentTypeValue); static CharSequence getMimeType(HttpMessage message); static CharSequence getMimeType(CharSequence contentTypeValue); static String formatHostnameForHttp(InetSocketAddress addr);  }### Answer:
@Test public void testGetCharsetAsRawCharSequence() { String QUOTES_CHARSET_CONTENT_TYPE = "text/html; charset=\"utf8\""; String SIMPLE_CONTENT_TYPE = "text/html"; HttpMessage message = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK); message.headers().set(HttpHeaderNames.CONTENT_TYPE, QUOTES_CHARSET_CONTENT_TYPE); assertEquals("\"utf8\"", HttpUtil.getCharsetAsSequence(message)); assertEquals("\"utf8\"", HttpUtil.getCharsetAsSequence(QUOTES_CHARSET_CONTENT_TYPE)); message.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/html"); assertNull(HttpUtil.getCharsetAsSequence(message)); assertNull(HttpUtil.getCharsetAsSequence(SIMPLE_CONTENT_TYPE)); }