code: private boolean isIncluded(final HttpServletRequest request) {
  		final String uri = (String) request.getAttribute("javax.servlet.include.request_uri");
  		final boolean includeRequest = !(uri == null);
  
  		if (includeRequest && log.isDebugEnabled()) {
  			log.debug("{} resulted in an include request. This is unusable, because"
  					+ "the response will be assembled into the overrall response. Not gzipping.",
  					request.getRequestURL());
  		}
  		return includeRequest;
  	}
docs: Checks if the request uri is an include. These cannot be gzipped.