Governs how empty elements (i.e. those without child elements) should be serialized.
Always minimize empty tags.
Always minimize empty tags. Note that this may be problematic for XHTML, in which
case scala.xml.Xhtml#toXhtml should be used instead.
Minimize empty tags if they were originally empty when parsed, or if they were constructed
with scala.xml.Elem#minimizeEmpty == true
Never minimize empty tags.