public OntologyDB(String filename) {
   try {
     // String modelFileName = filename;
     this.reloadOWLFile(filename);
   } catch (IllegalArgumentException e) {
     System.out.println("Caught Exception : " + e.getMessage());
   }
   this.reasoning();
 }
  public OntologyDB(ArrayList<String> filenames) {
    // create an empty model
    this.model = ModelFactory.createOntologyModel(PelletReasonerFactory.THE_SPEC);

    // this.model = ModelFactory.createDefaultModel();
    try {
      for (String filename : filenames) {
        // String modelFileName = filename;
        this.importOntology(filename);
      }
    } catch (IllegalArgumentException e) {
      System.out.println("Caught Exception : " + e.getMessage());
    }
    this.reasoning();
  }