### Question:
HttpRequest { public Map<String, String> getHeaders() { return headers; } HttpRequest(String method, URI uri); @SuppressWarnings("unchecked")  HttpRequest(String method, URI uri, Map<String, String> headers, InputStream content); String getMethod(); URI getUri(); Map<String, String> getHeaders(); InputStream getContent(); long getContentLength(); boolean isStreaming(); @SuppressWarnings("checkstyle:hiddenfield") void setStreaming(boolean isStreaming);  }### Answer:
@Test(expected = UnsupportedOperationException.class) public void testUnmodifierableHeaders() { request = new HttpRequest(method, uri); request.getHeaders().put("key", "value"); }