Fetches value for key (returns unwrapped value if `wrapItems` is `true`).
@param key {*}
@method sjl.stdlib.PriorityList#get
@overrides sjl.stdlib.SjlMap#get
@returns {*}
function (key) {
            var result = SjlMap.prototype.get.call(this, key);
            return this.wrapItems && result ? result.value : result;
        }