code: public void read(DwgFile dwgFile) throws IOException {
  		System.out.println("DwgFileV15Reader.read() executed ...");
  		this.dwgFile = dwgFile;
  		File f = new File(dwgFile.getFileName());
  		FileInputStream fis = new FileInputStream(f);
  		FileChannel fc = fis.getChannel();
  		long s = fc.size();
  		ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, s);
  		readDwgSectionOffsets(bb);
  		try {
  			readDwgObjectOffsets(bb);
  			//readDwgClasses(bb);
  		} catch (Exception e) {
  		    System.out.println("Error leyendo offsets y classes. Posible corrupci�n en" +
  		    		"el DWG file ...");
  		}
  		long t1 = System.currentTimeMillis();
  		readDwgObjects(bb);
  		long t2 = System.currentTimeMillis();
  		System.out.println("Tiempo empleado por readDwgObjects() = " + (t2-t1));
  	}
docs: Reads the DWG version 15 format
  
  @param dwgFile Represents the DWG file that we want to read
  @throws IOException When DWG file path is wrong