docs: public <R> R download(String uri,
  			ContentHandler<BasicHttpResponse, R> handler)
  			throws RedmineException {
  		final URI requestUri = configurator.addAPIKey(uri);
  		final HttpGet request = new HttpGet(requestUri);
          if (onBehalfOfUser != null) {
              request.addHeader("X-Redmine-Switch-User", onBehalfOfUser);
          }
          return errorCheckingCommunicator.sendRequest(request, handler);
      }