Having this Linq statement to create an XML

```
new XElement(ns + "SpecialRegisters",
  from reg in registers
  where reg.IsUpdateRegister
  select new XElement(ns + "UpdateRegisters",
    new XElement(ns + "RegID",
        new XAttribute("ID", registers.IndexOf(reg).ToString().PadLeft(2, '0'))
    )
  )
)

```

Is it possible to create a unique UpdateRegisters element with multiple RegID.
If there are no update registers there should not exist any UpdateRegisters element.