private function fillForm(Form $form, User $user)
{
$form['username']->setDefaultValue($user->getUsername());
$form['email']->setDefaultValue($user->getEmail());
$form['first_name']->setDefaultValue($user->getFirstName());
$form['last_name']->setDefaultValue($user->getLastName());
foreach ($user->getRoles() as $roleID => $role) {
// todo
$form['role']->setDefaultValue($roleID);
}
}