I have an entities that look like this:

class Customer
{
private $id;

 private $name;

 private $contact_user;

 private $new_contact_user;

}

class User
{
private $id;

 private $name;

}

Form connected with Customer has a field $new_contact_user of type UserType. Adding new contact user to customer is not required during adding or updating Customer. Whenever i leave UserType form blank i'm getting $new_contact_user as User entity filled with null values. How can I check if UserType form fields were left with blank during request ?