UserModel::getPermission

public function getPermission(string $permissionId): ?int
{
	$permissions = $this->getPermissions();

	$permissions[$permissionId] = $permissions[$permissionId] ?? null;

	if (is_array($permissions[$permissionId]))
	{
		$permissions[$permissionId] =
			isset($permissions[$permissionId][0])
				? (int)$permissions[$permissionId][0]
				: null
		;
	}

	return $permissions[$permissionId];
}