WebResponse.getContentAsString() fails to handle brotli stream data

[RuralHunter]

This is the test case to show the problem, most of it is copied from WebResponseDataTest:

@Test
    public void testWebResponse() throws Exception
    {
        final InputStream stream = getClass().getClassLoader().getResourceAsStream("testfiles/test.html.brotli");
        final byte[] zippedContent = IOUtils.toByteArray(stream);

        final List<com.gargoylesoftware.htmlunit.util.NameValuePair> headers = new ArrayList<>();
        headers.add(new com.gargoylesoftware.htmlunit.util.NameValuePair("Content-Encoding", "br"));

        final WebResponseData data = new WebResponseData(zippedContent, HttpStatus.SC_OK, "OK", headers);
        WebResponse response=new WebResponse(data,new URL("http://test.com"),HttpMethod.GET,1000);
        logger.info("content string:{}", response.getContentAsString());
        logger.info("body:{}", new String(data.getBody(), UTF_8));
    }

Just compare the output of the last 2 lines.