code: function visitEntry (pkey, context, callback) {
      _(context).chain().keys().each(function (key) {
          var entry = context[key], curkey = pkey?(pkey + '.' + key):key;
          if(_.isFunction(entry) || _.isString(entry) || _.isBoolean(entry) ||
             _.isArray(entry) || _.isNumber(entry) || _.isRegExp(entry)) {//entry is a leaf node
              callback(curkey, entry);
          } else {//entry is not a leaf node
              visitEntry (curkey, entry, callback)
          }
      });
  }
docs: Visit object hierachy structure