<is:ItemMaster>
  <is:ItemMasterHeader>
    <oi:ItemID agencyRole="Product_Number">some_number</oi:ItemID>
    <oi:ItemID agencyRole="Prefix_Number">some_number</oi:ItemID>
    <oi:ItemID agencyRole="Stock_Number">some_number</oi:ItemID>
    <oi:ManufacturerItemID>some_manufacturer_ID</oi:ManufacturerID>
    <is:Classification type="Group"></is:Classification>
    <is:Classification></is:Classification>