private void writeFgNode(FunctionallyGroundedNode fgNode,
NamedNode namedNode, ReferencingNaturalizer naturalizer,
ZipOutputStream zipOut) throws IOException {
String relativePath;
try {
relativePath = new URI(ReferencingNaturalizer.rootURL).relativize(
namedNode.getURIRef(), URI.SAMEDOCUMENT | URI.ABSOLUTE
| URI.RELATIVE | URI.PARENT);
} catch (MalformedURIException e) {
throw new RuntimeException(e);
}