#vulnerable code 
                              @Override
  public void handlePeerDisconnected(SharingPeer peer) {
    final SharedTorrent peerTorrent = peer.getTorrent();
    Peer p = new Peer(peer.getIp(), peer.getPort());
    p.setPeerId(peer.getPeerId());
    p.setTorrentHash(peer.getHexInfoHash());
    PeerUID peerUID = new PeerUID(p.getStringPeerId(), p.getHexInfoHash());
    SharingPeer sharingPeer = this.peersStorage.removeSharingPeer(peerUID);
    logger.debug("Peer {} disconnected, [{}/{}].",
            new Object[]{
                    peer,
                    getConnectedPeers().size(),
                    this.peersStorage.getSharingPeers().size()
            });
  } 
                            #location 7 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                              @Override
  public void handlePeerDisconnected(SharingPeer peer) {
    final SharedTorrent peerTorrent = peer.getTorrent();
    Peer p = new Peer(peer.getIp(), peer.getPort());
    p.setPeerId(peer.getPeerId());
    p.setTorrentHash(peer.getHexInfoHash());
    PeerUID peerUID = new PeerUID(p.getAddress(), p.getHexInfoHash());
    SharingPeer sharingPeer = this.peersStorage.removeSharingPeer(peerUID);
    logger.debug("Peer {} disconnected, [{}/{}].",
            new Object[]{
                    peer,
                    getConnectedPeers().size(),
                    this.peersStorage.getSharingPeers().size()
            });
  }