How to use populate placeholders in XML template using Scala XML?

I have the following XML template and using Scala XML I'd like to have those placeholders properly populated but I can't find the API for this. Can anyone advice whether this is possible at all?

<?xml version="1.0" encoding="UTF-8" ?>
<testsuite failures={failures} time={time} errors={errors} skipped="0" tests={tests} name="k4unit">
    <properties />
</testsuite>

The Scala code so far:

scala> import scala.xml.XML
import scala.xml.XML

scala> val xml = XML.loadFile("./testcases/TEST-k4unit-template.xml")
xml: scala.xml.Elem = 
<testsuite name="k4unit" tests={tests} skipped="0" errors={errors} time={time} failures={failures}>
  <properties/>
</testsuite>

I'd like to have the attributes tests, errors, time and failures populated with dynamic values.