/**
* Follows another user
*
* @param User $user
*
* @throws FollowerException If the user follows already the user to follow
* @throws ActivationException If the target user to follow is not activated
*/
public function follow(User $user)
{
$this->ensureActivated();
if (!$user->isActivated()) {
throw new ActivationException();
}
if ($this->follows($user->getCredentials()->getUsername())) {
throw new FollowerException();
}
$this->following->add($user);
}
