SoapClient PHP不返回属性

I am facing difficulties working on a workday Soap Api. I use PHP SoapClient to retrieve data from it. The problem is that requests executed via SoapClient don't return any arguments. Response is a stdClass. Using SoapUI there's no problem.

Exemple of response from SoapUI:

<wd:Job_Posting_Location_Data>
                 <wd:Primary_Location_Reference wd:Descriptor="UK Commerce">
                    <wd:ID wd:type="WID">70b38acca79b0160f868181d0819a827</wd:ID>
                    <wd:ID wd:type="Location_ID">UST</wd:ID>
                 </wd:Primary_Location_Reference>
              </wd:Job_Posting_Location_Data>

With response from SoapClient all values above are available except "wd:Descriptor" attributes. Do you have any suggestions or clue on how to get this attributes data in the SoapClient response like in SoapUI ?