How to test inner arrays with phpunit

I have to test an array with inner arrays.

my array looks like the following.

$testdata=Array
    (
        [0] => Array
            (
                [label] => 'Ammy'
                [idr] => 'user7'
                [rel] => 7
            )

        [1] => Array
            (
                [label] => 'sidh'
                [idr] => user8
                [rel] => 8
            )

        [2] => Array
            (
                [label] => 'Alan'
                [idr] => 'user9'
                [rel] => 9
            )
    )

in this case my requirement is to assert whether the keys for inner array present using assertArrayHasKey() assertion of phpunit. I tried to do it like this

foreach ($testdata as $values) {
 //print_r($values);
  $this->assertArrayHasKey('idr', $values);
  $this->assertArrayHasKey('rel', $values);

}

but this is not working for me. even the control does not go inside the foreach() loop.

please suggest me some solution for this.

foreach ($testdata as $values) {
 //print_r($values);
  $this->assertArrayHasKey('idr', $values);
  $this->assertArrayHasKey('rel', $values);

}

this part in my question works fine. actually i was not getting the array itself in the test scenario. so it was not going inside the foreach(). now it is solved. i had a mistake in passing args to the function.