index.js
function(memberName) {
        var parent = this.super;
        do { parent = Object.getPrototypeOf(parent); } while (!parent.hasOwnProperty(memberName));
        return parent && parent[memberName];
    }
function(memberName) {
        var parent = this.super;
        do { parent = Object.getPrototypeOf(parent); } while (!parent.hasOwnProperty(memberName));
        return parent && parent[memberName];
    }
function ( memberName ) { var parent = this . super ; do { parent = Object . getPrototypeOf ( parent ) ; } while ( ! parent . hasOwnProperty ( memberName ) ) ; return parent && parent [ memberName ] ; }
Find member on prototype chain beginning with super class.
@param {string} memberName
@returns {undefined|*} `undefined` if not found; value otherwise.
Find member on prototype chain beginning with super class .