private function isDataSetProperly(array $data): bool
    {
        return (isset($data["in"]) && isset($data["out"]) && isset($data["from"]) && isset($data["to"]));
    }
private function isDataSetProperly(array $data): bool
    {
        return (isset($data["in"]) && isset($data["out"]) && isset($data["from"]) && isset($data["to"]));
    }
private function isDataSetProperly ( array $ data ) : bool { return ( isset ( $ data [ "in" ] ) && isset ( $ data [ "out" ] ) && isset ( $ data [ "from" ] ) && isset ( $ data [ "to" ] ) ) ; }
Checks if the data source for import is valid.

@param array $data

@return bool
Checks if the data source for import is valid .