Converts an object into its XML representation; this usually means
that the object's toString() method is called and the result used
to create a DOM Text object.
If the given Element has no text content, a new Text node added with
the given text; otherwise, the first Text node will have its value
changed to the given text.
This is a convenience method that calls toFile(Node, File, boolean)
with the last parameter set to "true" (to add the standard XML
header to the new XML file).
This is a convenience method that serializes the given XML tree
with the XML header and indentation; it is the equivalent of
calling toString(Node, boolean) with the last parameter set to
"true".