lib/util.js
function (obj, name, Prop, fallback) {
        return _.has(obj, name) ? (new Prop(obj[name])) : fallback;
    }
function (obj, name, Prop, fallback) {
        return _.has(obj, name) ? (new Prop(obj[name])) : fallback;
    }
function ( obj , name , Prop , fallback ) { return _ . has ( obj , name ) ? ( new Prop ( obj [ name ] ) ) : fallback ; }
Creates a property on an object, with the given type.

@param {Object} obj
@param {String} name
@param {Property} Prop
@param {*} [fallback]
@returns {Prop|undefined}
Creates a property on an object with the given type .