code: function(component, selector) {
              if (!selector) {
                  return true;
              }
              var selectors = selector.split(','),
                  length = selectors.length,
                  i = 0,
                  query;
  
              for (; i < length; i++) {
                  selector = Ext.String.trim(selectors[i]);
                  query = this.cache[selector] || (this.cache[selector] = this.parse(selector));
                  if (query.is(component)) {
                      return true;
                  }
              }
              return false;
          }
docs: Tests whether the passed Component matches the selector string.
  @param {Ext.Component} component The Component to test
  @param {String} selector The selector string to test against.
  @return {Boolean} True if the Component matches the selector.
  @member Ext.ComponentQuery