private String getHeadNoun(String uri) {
String[] tokens = lexicalize(uri);
// if we have multiple tokens, get the head noun
String head;
if (tokens.length > 1) {
head = Joiner.on(" ").join(tokens);
Annotation document = new Annotation(head);
pipeline.annotate(document);
CoreMap sentence = document.get(SentencesAnnotation.class).get(0);
Tree tree = sentence.get(TreeAnnotation.class);
Tree headTree = headFinder.determineHead(tree);
// we assume that the last occurring NN is the head noun
List<Tree> leaves = headTree.getLeaves();
head = leaves.get(leaves.size() - 1).label().value();
} else {
head = tokens[0];
}
return head;
}