Custom fields not included in response

[JeremyLopez]

I am trying to include the ReferredBy attribute in the ClientService.get_clients function. In the docs you can state:

<Fields>
    <string>Clients.CustomClientFields</string>
</Fields>

but when I do that in my request:

"Fields"=>{
    "string"=>"Clients.ReferredBy"
}

the field is not included when I call:

response = MindBody::Services::ClientService.get_clients(search_params)
response.result[:clients]

I can however access the field by parsing the response as follows:

response = MindBody::Services::ClientService.get_clients(search_params)
response.response.hash[:envelope][:body][:get_clients_response][:get_clients_result][:clients][:referred_by]

Is there any way to have this included in the standard response so I don't need to manually parse the response?