code: 	void toHtml() throws IOException {
  		writeBackAndRefreshLinks();
  		writeln("<br/>");
  
  		assert sessionsInformations != null;
  		if (sessionsInformations.isEmpty()) {
  			writeln("#Aucune_session#");
  			return;
  		}
  		writeTitle("system-users.png", getString("Sessions"));
  		writeSessions(sessionsInformations);
  		long totalSerializedSize = 0;
  		int nbSerializableSessions = 0;
  		for (final SessionInformations sessionInformations : sessionsInformations) {
  			final int size = sessionInformations.getSerializedSize();
  			if (size >= 0) {
  				totalSerializedSize += size;
  				nbSerializableSessions++;
  			}
  		}
  		final long meanSerializedSize;
  		if (nbSerializableSessions > 0) {
  			meanSerializedSize = totalSerializedSize / nbSerializableSessions;
  		} else {
  			meanSerializedSize = -1;
  		}
  		writeln("<div align='right'>"
  				+ getFormattedString("nb_sessions", sessionsInformations.size()) + "<br/><br/>"
  				+ getFormattedString("taille_moyenne_sessions", meanSerializedSize) + "</div>");
  	}
  
  