docs: protected ExtensionHttpSessions getExtensionHttpSessions() {
  		if (extensionHttpSessions == null) {
  			extensionHttpSessions = Control.getSingleton().getExtensionLoader().getExtension(ExtensionHttpSessions.class);
  			if (extensionHttpSessions == null)
  				log.error("Http Sessions Extension should be enabled for the "
  						+ ExtensionUserManagement.class.getSimpleName() + " to work.");
  		}
  		return extensionHttpSessions;
  
  	}