Permissions::canPerform

public function canPerform($entityCode, $actionCode, $minimumPermission = null)
{
	$permissionMap = $this->getMap();
	if(!isset($permissionMap[$entityCode][$actionCode]))
		throw new ArgumentException('Unknown entity or action code');

	if(is_null($minimumPermission))
	{
		$result = (
			isset($this->permissions[$entityCode][$actionCode]) &&
			$this->permissions[$entityCode][$actionCode] > self::PERMISSION_NONE
		);
	}
	else
	{
		$result = (
			isset($this->permissions[$entityCode][$actionCode]) &&
			$this->permissions[$entityCode][$actionCode] >= $minimumPermission
		);
	}

	return $result;
}