How to use the parse-torrent function in parse-torrent

return new Promise((resolve, reject) => {
			if(!this._hash){
				this._state = State.INVALID;
				return reject(INVALID_ERROR());
			}

			// Do not init() twice
			if(this.isInitialized())
				return reject(new TypeError('Torrent '+self._hash+' is already initialized'));

			var parsed;
			try {
				parsed = parseTorrent(this._source);

			} catch(err) {
				return reject(err);
			}
			self._init = true;
			self._title = parsed.name || 'loading title...';
			self._state = State.LOADING;
			
			this.emit('change');
			this.emit('change:state');
			this.emit('initializing');

			this._torrent = this._config.client.add(this._source, (torr) => {
				console.log('TORRENT ADDED');
				this._state = State.CONNECTING;
				this.emit('change');

onAddTorrent (payload) {
		console.log('payload', payload);
		let hash = parseTorrent(payload.hash).infoHash;

		client.addTorrent(payload.hash).then((torrent) => {
			this.torrents[hash] = torrent;
			torrent.on('change', () => {
				this.emit('change');
			});
			this.emit('change');
		}).catch((err) => {
			console.log(err);
			this.emit('change')
		});

	},

return new Promise((resolve, reject) => {
			console.log('create', source, config);

			try {
				let parsed = parseTorrent(source);
				let trt = new Torrent(parsed.infoHash, source, config);
				resolve(trt);
			} catch (err) {
				console.log(err);
				return reject(err);
			}
		});
	}

fs.readFile(paths[0], (err, data) => {
          if (err) {
            showToast(err.message, 'error');
          }
          const torrent = parseTorrent(data);

          torrent.size = torrent.size || prettyBytes(torrent.length);

          this.props.dispatch({
            type: 'ADD_TO_DOWNLOAD_LIST',
            payload: torrent,
          });

          ipcRenderer.send('add_torrent_to_download', torrent.infoHash);
        });
      },

addMagnetUrl = () => {
    const value = this.magnetInputRef.value;
    if (!isMagnet(value)) {
      showToast('This is not a valid magnet URL', 'error');
      return;
    }

    const { infoHash } = parseTorrent(value);

    this.setState({
      loadingMagnetInfo: true,
    });

    ipcRenderer.on('decoded_infoHash', (event, torrent) => {
      this.closeMagnetUrlModal();

      this.props.dispatch({
        type: 'ADD_TO_DOWNLOAD_LIST',
        payload: torrent,
      });
    });

    ipcRenderer.send('decode_infohash_and_add_to_download', infoHash);
  };

wstream.on('finish', () => {
        try {
          let length = parseTorrent(fs.readFileSync(torrentPath)).length;
          res({ length });
        } catch (exception) {
          rej(exception);
        } finally {
          fs.unlink(torrentPath);
        }
      });
    }).catch(rej);