Datamapper include_related group values to one object

[eluser]Sport_Billy[/eluser]
I am having 3 tables

Code:

customers
   id  
   firstname
   lastname
deseases
   id
   desease_name
customers_deseases
   id
   customer_id
   desease_id

And i want to get the deseases of each customer.
For example let's say that customer John Smith has desease1 and desease2.
When using this code:

Code:

$customer = new Customer();
$customer->include_related('desease', array('desease_name'), true, true);
$customers = $customer->get();

And trying to see the results like this:

Code:

foreach($customers as $c){
                echo $c->firstname . $c->lastname;
                echo "<br/>";
                foreach($c->desease as $cd)
                {
                    echo $cd->desease_name;  
                    echo "<br/>";
                }
        }

The returning object has the customer in 2 separate objects like this

Code:

John Smith desease1
John Smith desease2

While i want something like this:

Code:

John Smith
desease1
desease2