Print a debug message that starts with the abbreviated class name of this,
but only if messageLevel is greater than the debug level for
this class (see above).
Download an XML file from a source to a target location with minimal effort,
unless the XML file already exists at the target location, in which case,
do nothing.
Download and uncompress a zip file from a source to a target location with minimal effort,
unless the zip file already exists at the target location, in which case,
do nothing.