public void writeOntologyHeader(OWLOntology ontology) {
   event = new RendererEvent(this, ontology);
   fireFrameRenderingPrepared(ONTOLOGY.toString());
   write(ONTOLOGY.toString());
   write(":");
   writeSpace();
   if (!ontology.isAnonymous()) {
     int indent = getIndent();
     writeFullURI(ontology.getOntologyID().getOntologyIRI().toString());
     writeNewLine();
     pushTab(indent);
     if (ontology.getOntologyID().getVersionIRI() != null) {
       writeFullURI(ontology.getOntologyID().getVersionIRI().toString());
     }
     popTab();
   }
   fireFrameRenderingStarted(ONTOLOGY.toString());
   writeNewLine();
   for (OWLImportsDeclaration decl : ontology.getImportsDeclarations()) {
     fireSectionItemPrepared(IMPORT.toString());
     write(IMPORT.toString());
     write(":");
     writeSpace();
     fireSectionRenderingStarted(IMPORT.toString());
     writeFullURI(decl.getURI().toString());
     writeNewLine();
     fireSectionRenderingFinished(IMPORT.toString());
   }
   writeNewLine();
   writeSection(ANNOTATIONS, ontology.getAnnotations(), ",", true);
   fireFrameRenderingFinished(ONTOLOGY.toString());
 }
 public TurtleRenderer(
     OWLOntology ontology, OWLOntologyManager manager, Writer writer, OWLOntologyFormat format) {
   super(ontology, manager, format);
   this.writer = new PrintWriter(writer);
   pending = new HashSet<RDFResourceNode>();
   pm = new DefaultPrefixManager();
   if (!ontology.isAnonymous()) {
     pm.setDefaultPrefix(ontology.getOntologyID().getOntologyIRI() + "#");
   }
   if (format instanceof PrefixOWLOntologyFormat) {
     PrefixOWLOntologyFormat prefixFormat = (PrefixOWLOntologyFormat) format;
     for (String prefixName : prefixFormat.getPrefixNames()) {
       pm.setPrefix(prefixName, prefixFormat.getPrefix(prefixName));
     }
   }
   base = "";
 }