code: public void read() throws IOException {
          System.out.println("DwgFile.read() executed ...");
          setDwgVersion();
          if (dwgVersion.equals("R13")) {
              dwgReader = new DwgFileV14Reader();
              dwgReader.read(this);
          } else if (dwgVersion.equals("R14")) {
              dwgReader = new DwgFileV14Reader();
              dwgReader.read(this);
          } else if (dwgVersion.equals("R15")) {
              dwgReader = new DwgFileV15Reader();
              dwgReader.read(this);
          } else if (dwgVersion.equals("Unknown")) {
              throw new IOException("DWG version of the file is not supported.");
          }
      }
docs: Reads a DWG file and put its objects in the dwgObjects Vector
  This method is version independent
  
  @throws IOException If the file location is wrong