Nationalities in PHP

nationalities.php

(new \PragmaRX\Countries\Package\Countries())
    ->all()
    ->keyBy('iso_3166_1_alpha2')
    ->filter(function ($value, $key) {
        return (bool)strlen($key);
    })
    ->pluck('demonyms.eng.m')
    ->filter(function($name){
        return !empty($name);
    })
    ->unique()
    ->mapWithKeys(function($item){
        return [$item =>  $item];
    })
    ->sort(function($a, $b){
        $at = iconv('UTF-8', 'ASCII//TRANSLIT', $a);
        $bt = iconv('UTF-8', 'ASCII//TRANSLIT', $b);
        return strcmp($at, $bt);
    })

This code pulls out the nationalities from this package and sorts them alphabetically.