XMLEncoder shares equal Integer objects, so a node's x coordinate can be
written as a reference to the result of JSidebarButton.getIconTextGap().
GetterDefaults constructs the classes like XMLDecoder does and records
what the getters return (packages/fls/src/javaDefaults.json).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
