code: function(glyph) {
          var me = this,
              iconCmp = me.iconCmp;
          
          if (!me.iconCmp) {
              me.initIconCmp();
              me.insert(0, me.iconCmp);
          } else if (iconCmp) {
              if (glyph) {
                  me.iconCmp.setGlyph(glyph);
              } else {
                  me.iconCmp.destroy();
                  delete me.iconCmp;
              }
          }
      }
docs: Sets glyph that provides the icon image for this header.  This method will replace any existing
  glyph if one has already been set.
  @param {Number/String} glyph the numeric charCode or string charCode/font-family.
  This parameter expects a format consistent with that of {@link #glyph}