Remove multiple data from firebase

I uses a wrap of kreait/firebase-php for processing needed requests. I need to realize removing old data, but them too much for removing data one by one entry. How I can to remove multiple data by one request? this is an example of my current code:

$keys = [..keys of data ..];
foreach ($keys as $key) {
   $firebase->getReference(<collection> . '/' . $key)->remove();
}