```
function yielding()
{
    for ($i = 0; $i < 10; $i++) {
        var_dump(yield);
    }
}

$y = yielding();

foreach ($y as $val) {
    $y->send('foo');
}

```

output:

```
string(3) "foo"
NULL
string(3) "foo"
NULL
string(3) "foo"
NULL
string(3) "foo"
NULL
string(3) "foo"

```

i expected the output to be: 10 time `string(3) "foo"`, but instead the output is one `NULL` and one `string(3) "foo"` (9 times). why is it?
does generator->send() skip one iteratoration?