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
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;
        }