code: public ClientResponse execute(ClientExecutionContext ctx) throws Exception {
          String encoding = ctx.getRequest().getHeaders().getFirst(HttpHeaders.ACCEPT_ENCODING);
          if (encoding == null) {
              ctx.getRequest().header(HttpHeaders.ACCEPT_ENCODING, "lzf");
          } else {
              if (!encoding.contains("lzf")) {
                  encoding += ", lzf";
                  ctx.getRequest().header(HttpHeaders.ACCEPT_ENCODING, encoding);
              }
          }
          return ctx.proceed();
      }
docs: Set headers to advertise ability to accept LZF compression  <p/>
  Check if client response has HTTP header "Accept-Encoding" set: <p/>
  <ul>   <li>- If none, set header to "lzf", if has a header, add lzf to the list</li></ul>
  @param ctx Client execution context
  @return Response with headers appended
  @throws Exception