public static XMLExporter getInstance() {
        return new XMLExporter();
    }
Sets the number of spaces used to indent nested tags.
@param indentSpaces The number of spaces to indent for each level of nesting.  Default is 4.
Pass 0 to disable pretty printing and write document without adding any whitespace.
jme3-plugins/src/xml/java/com/jme3/export/xml/XMLExporter.java