このように models.User.fromURI を呼び出すと
models.User.fromURI("spotify:user:" + user, function (user) {
$(div).html("<b ><a style=\"color:#FFFFFF\" href=\"spotify:user:" + user.username + "\">" + user + "</a></b><br />" + text + "");
});
このエラーが発生します
Uncaught TypeError: Object #<Object> has no method 'getUserByUsername'