preserve recipients in the sendgrid API

I'm sending an email to multiple recipients using the sendgrid API !

<?php


$email = new SendGrid\Email();
$sendgrid = new SendGrid('API_KEY');

$email
    ->addTo(array('first@mail.com','second@mail.com'..))
    ->setFrom('my@mail.com')
    ->setSubject('Subject goes here')
    ->setText('Hello World!')
    ->setHtml('<strong>Hello World!</strong>')
;

$sendgrid->send($email);

Now, I wanna know if there is any way to hide the second email in the "To" header for the first email?