View file PF.Src/Api/Message/Object.php

<?php

namespace Api\Message;

class Object extends \Core\Objectify {
	public $id;
	public $preview;
	public $time;
	public $users;
	public $thread_name;

	public function __construct($object) {

		$map = [
			'id' => (int) $object['thread_id'],
			'preview' => (isset($object['preview']) ? $object['preview'] : null),
			'time' => (int) $object['time_stamp'],
			'thread_name' => $object['thread_name'],
			'users' => []
		];

		foreach ($object['users'] as $user) {
			$map['users'][] = $this->_build($user);
		}

		parent::__construct($map);

		if (!isset($object['preview'])) {
			unset($this->preview);
		}
	}
}