code: function(event) {
  				var sPreviousHash = History.getInstance().getPreviousHash();
  
  				if (sPreviousHash !== undefined) {
  					// The history contains a previous entry
  					if (sPreviousHash.indexOf("search/") === 0) {
  						this.getRouter().navTo("search", {searchParam: sPreviousHash.split("/")[1]}, false);
  					} else {
  						history.go(-1);
  					}
  				} else {
  					var sCurrentHash = window.location.hash;
  
  					if (sCurrentHash.indexOf("#/topic/") == 0) {
  						this.getRouter().navTo("topic", {}, true);
  					} else if (sCurrentHash.indexOf("#/api/") == 0) {
  						this.getRouter().navTo("api", {}, true);
  					}
  				}
  			}
docs: Event handler  for navigating back.
  It checks if there is a history entry. If yes, history.go(-1) will happen.
  If not, it will replace the current entry of the browser history with the master route.
  @public