code: function(cls) {
          var me = this;
  
          me.activeThreadId++;
          cls = cls || '';
  
          if (me.rendered) {
              if (me.currIconCls) {
                  me.statusEl.removeCls(me.currIconCls);
                  me.currIconCls = null;
              }
              if (cls.length > 0) {
                  me.statusEl.addCls(cls);
                  me.currIconCls = cls;
              }
          } else {
              me.currIconCls = cls;
          }
          return me;
      }
docs: Convenience method for setting the status icon directly.  For more flexible options see {@link #setStatus}.
  See {@link #iconCls} for complete details about customizing the icon.
  @param {String} iconCls (optional) The icon class to set (defaults to '', and any current icon class is removed)
  @return {Ext.ux.statusbar.StatusBar} this