public Relationship[] relationships(String genome){
  final Collection<Relationship> col=mRelationships.get(genome);
  return col == null ? EMPTY_REL : col.toArray(new Relationship[col.size()]);
}

public Relationship [ ] relationships ( String genome ) { final Collection < Relationship > col = mRelationships . get ( genome ) ; return col == null ? EMPTY_REL : col . toArray ( new Relationship [ col . size ( ) ] ) ; }
get all relationships involving a genome .
