DateTime::createFromFormat(), date_create_from_format() returns original DateTime object.

```php
$dt1 = DateTime::createFromFormat('U', 0);
var_dump(get_class($dt1));
```
returns

```php
string(8) "DateTime"
```

in this case, I want get TimecopDateTime object.

i got error when some method has DateTime type hinting.

```php
function setDatetime(DateTime $date) {
}

//

setDatetime(DateTime::createFromFormat('U', 0)); // <-- error 

```

error message like:

    Argument 1 passed to setDatetime() must be an instance of TimecopDateTime, instance of DateTime given