understandthis.php

<?php

public function options()
{
    $value = $this->value;

    $mapped = array_map(function($k, $v) use ($value) {
     return array(
        'value'    => $k,
        'display'  => $v,
        'selected' => ($value === $k),
      );
    },  array_keys($this->options), $this->options);

    return $mapped;
}