function selectXPath(expression) {
    "use strict";
    return {
        type: 'xpath',
        path: expression,
        toString: function() {
            return this.type + ' selector: ' + this.path;
        }
    };
}
Shortcut to build an XPath selector object.

@param  String  expression  The XPath expression
@return Object
@see    http://casperjs.org/selectors.html