Duplicate elements in soap request using wash_out gem in Ruby

Question

I'm developing a SOAP service using wash_out gem in Ruby. I have a soap request where I'll be getting duplicate elements (Unique ID in the request given below) in soap request. But I can't find a way to define these elements in the args parameter.

The SOAP request is :

<OTA_CancelRQ Version="2.1" EchoToken="201403211421"
 xmlns="http://www.opentravel.org/OTA/2003/05"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

 <UniqueID ID="859623" Type="501"/>

 <UniqueID ID="ABCDEF" Type="502"/>

 <UniqueID ID="123456" Type="10"/>

 <Reasons>
 <Reason>business plan changed</Reason>
 </Reasons>
</OTA_CancelRQ>

Here is the code in my wash out controller :

soap_service namespace: 'urn:WashOut'

    soap_action "OTA_CancelRQ",
                  :args => {
                    :OTA_CancelRQ =>{

                      :UniqueID => {
                        :@ID => :integer,
                        :@Type => :integer
                      },
                      :Reasons => [{:Reason => :string }]
                    }},
                  :return => :string,
                  :to => :cancel_booking

These args generate a WSDL with with only one UniqueId element. I have tried defining the UniqueId multiple times in the args but it is generating only one UniqueId element.