code: protected boolean isIncludeStackTrace(ServerRequest request, MediaType produces) {
  		ErrorProperties.IncludeStacktrace include = this.errorProperties
  				.getIncludeStacktrace();
  		if (include == ErrorProperties.IncludeStacktrace.ALWAYS) {
  			return true;
  		}
  		if (include == ErrorProperties.IncludeStacktrace.ON_TRACE_PARAM) {
  			return isTraceEnabled(request);
  		}
  		return false;
  	}
docs: Determine if the stacktrace attribute should be included.
  @param request the source request
  @param produces the media type produced (or {@code MediaType.ALL})
  @return if the stacktrace attribute should be included