How to use the graphlib.converter function in graphlib

*
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
module.exports =  {
  Digraph: require('graphlib').Digraph,
  Renderer: require('./lib/Renderer'),
  json: require('graphlib').converter.json,
  layout: require('dagre').layout,
  version: require('./lib/version')
};

},{"./lib/Renderer":3,"./lib/version":4,"dagre":11,"graphlib":28}],3:[function(require,module,exports){
var layout = require('dagre').layout;

*
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
module.exports =  {
  Digraph: require('graphlib').Digraph,
  Renderer: require('./lib/Renderer'),
  json: require('graphlib').converter.json,
  layout: require('dagre').layout,
  version: require('./lib/version')
};

},{"./lib/Renderer":3,"./lib/version":4,"dagre":11,"graphlib":28}],3:[function(require,module,exports){
var layout = require('dagre').layout;