/**
  * Adds a mapping from an ontology IRI to an ontology document IRI which has a base of this mapper
  * and a specified local name - in other words the document IRI will be determined by resolving
  * the local name against the URI base of this mapper.
  */
 public void addMapping(IRI ontologyIRI, String localName) {
   IRI documentIRI = base.resolve(localName);
   iriMap.put(ontologyIRI, documentIRI);
 }