@Override
  public void store(Item item) throws IOException {
    String userId = item.getUserId();
    String tweetId = item.getId();
    long timestamp = item.getPublicationTime();
    //		String title = item.getTitle();

    Vertex source = getOrCreateVertex(userId, vertexUserId);

    // handle mentions
    String[] mentions = item.getMentions();
    for (String userMention : mentions) {
      Edge edge;
      // handle retweets
      if (!item.isOriginal()) {
        String userRetweets = item.getReferencedUserId();
        Vertex destination = getOrCreateVertex(userRetweets, vertexUserId);
        edge = titanGraph.addEdge(null, source, destination, edgeReTweets);
        //				edge.setProperty("title", title);
      } else {
        Vertex destination = getOrCreateVertex(userMention, vertexUserId);
        edge = titanGraph.addEdge(null, source, destination, edgeMentions);
        //				edge.setProperty("title", title);
      }
      edge.setProperty(edgePropertyTweedId, tweetId);
      edge.setProperty(edgePropertyTimestamp, timestamp);
    }

    titanGraph.commit();
  }