Program: 51000
Project: 51000
Buggy source:
private void relabelGraph2MultisetLabels(DirectedGraph<Vertex<Map<Integer,StringBuilder>>,Edge<Map<Integer,StringBuilder>>> graph,int startLabel){
  Map<String,Bucket<VertexIndexPair>> bucketsV=new HashMap<String,Bucket<VertexIndexPair>>();
  Map<String,Bucket<EdgeIndexPair>> bucketsE=new HashMap<String,Bucket<EdgeIndexPair>>();
  for (int i=startLabel; i < labelCounter; i++) {
    bucketsV.put(Integer.toString(i),new Bucket<VertexIndexPair>(Integer.toString(i)));
    bucketsE.put(Integer.toString(i),new Bucket<EdgeIndexPair>(Integer.toString(i)));
  }
  if (reverse) {
    for (    Edge<Map<Integer,StringBuilder>> edge : graph.getEdges()) {
      for (      int index : edge.getLabel().keySet()) {
        bucketsV.get(edge.getLabel().get(index).toString()).getContents().add(new VertexIndexPair(graph.getSource(edge),index + 1));
      }
    }
    for (    Vertex<Map<Integer,StringBuilder>> vertex : graph.getVertices()) {
      Collection<Edge<Map<Integer,StringBuilder>>> v2=graph.getInEdges(vertex);
      for (      int index : vertex.getLabel().keySet()) {
        for (        Edge<Map<Integer,StringBuilder>> e2 : v2) {
          if (e2.getLabel().containsKey(index)) {
            bucketsE.get(vertex.getLabel().get(index).toString()).getContents().add(new EdgeIndexPair(e2,index));
          }
        }
      }
    }
  }
 else {
    for (    Edge<Map<Integer,StringBuilder>> edge : graph.getEdges()) {
      for (      int index : edge.getLabel().keySet()) {
        bucketsV.get(edge.getLabel().get(index).toString()).getContents().add(new VertexIndexPair(graph.getDest(edge),index));
      }
    }
    for (    Vertex<Map<Integer,StringBuilder>> vertex : graph.getVertices()) {
      Collection<Edge<Map<Integer,StringBuilder>>> v2=graph.getOutEdges(vertex);
      for (      int index : vertex.getLabel().keySet()) {
        if (index > 0) {
          for (          Edge<Map<Integer,StringBuilder>> e2 : v2) {
            bucketsE.get(vertex.getLabel().get(index).toString()).getContents().add(new EdgeIndexPair(e2,index - 1));
          }
        }
      }
    }
  }
  for (  Edge<Map<Integer,StringBuilder>> edge : graph.getEdges()) {
    for (    int i : edge.getLabel().keySet()) {
      edge.getLabel().get(i).append("String_Node_Str");
    }
  }
  for (  Vertex<Map<Integer,StringBuilder>> vertex : graph.getVertices()) {
    for (    int i : vertex.getLabel().keySet()) {
      vertex.getLabel().get(i).append("String_Node_Str");
    }
  }
  for (int i=startLabel; i < labelCounter; i++) {
    Bucket<VertexIndexPair> bucketV=bucketsV.get(Integer.toString(i));
    for (    VertexIndexPair vp : bucketV.getContents()) {
      vp.getVertex().getLabel().get(vp.getIndex()).append(bucketV.getLabel());
      vp.getVertex().getLabel().get(vp.getIndex()).append("String_Node_Str");
    }
    Bucket<EdgeIndexPair> bucketE=bucketsE.get(Integer.toString(i));
    for (    EdgeIndexPair ep : bucketE.getContents()) {
      ep.getEdge().getLabel().get(ep.getIndex()).append(bucketE.getLabel());
      ep.getEdge().getLabel().get(ep.getIndex()).append("String_Node_Str");
    }
  }
}

Fixed version (ground truth):
private void relabelGraph2MultisetLabels(DirectedGraph<Vertex<Map<Integer,StringBuilder>>,Edge<Map<Integer,StringBuilder>>> graph){
  Map<String,Bucket<VertexIndexPair>> bucketsV=new HashMap<String,Bucket<VertexIndexPair>>();
  Map<String,Bucket<EdgeIndexPair>> bucketsE=new HashMap<String,Bucket<EdgeIndexPair>>();
  for (int i=startLabel; i < labelCounter; i++) {
    bucketsV.put(Integer.toString(i),new Bucket<VertexIndexPair>(Integer.toString(i)));
    bucketsE.put(Integer.toString(i),new Bucket<EdgeIndexPair>(Integer.toString(i)));
  }
  if (reverse) {
    for (    Edge<Map<Integer,StringBuilder>> edge : graph.getEdges()) {
      for (      int index : edge.getLabel().keySet()) {
        bucketsV.get(edge.getLabel().get(index).toString()).getContents().add(new VertexIndexPair(graph.getSource(edge),index + 1));
      }
    }
    for (    Vertex<Map<Integer,StringBuilder>> vertex : graph.getVertices()) {
      Collection<Edge<Map<Integer,StringBuilder>>> v2=graph.getInEdges(vertex);
      for (      int index : vertex.getLabel().keySet()) {
        for (        Edge<Map<Integer,StringBuilder>> e2 : v2) {
          if (e2.getLabel().containsKey(index)) {
            bucketsE.get(vertex.getLabel().get(index).toString()).getContents().add(new EdgeIndexPair(e2,index));
          }
        }
      }
    }
  }
 else {
    for (    Edge<Map<Integer,StringBuilder>> edge : graph.getEdges()) {
      for (      int index : edge.getLabel().keySet()) {
        bucketsV.get(edge.getLabel().get(index).toString()).getContents().add(new VertexIndexPair(graph.getDest(edge),index));
      }
    }
    for (    Vertex<Map<Integer,StringBuilder>> vertex : graph.getVertices()) {
      Collection<Edge<Map<Integer,StringBuilder>>> v2=graph.getOutEdges(vertex);
      for (      int index : vertex.getLabel().keySet()) {
        if (index > 0) {
          for (          Edge<Map<Integer,StringBuilder>> e2 : v2) {
            bucketsE.get(vertex.getLabel().get(index).toString()).getContents().add(new EdgeIndexPair(e2,index - 1));
          }
        }
      }
    }
  }
  for (  Edge<Map<Integer,StringBuilder>> edge : graph.getEdges()) {
    for (    int i : edge.getLabel().keySet()) {
      edge.getLabel().get(i).append("String_Node_Str");
    }
  }
  for (  Vertex<Map<Integer,StringBuilder>> vertex : graph.getVertices()) {
    for (    int i : vertex.getLabel().keySet()) {
      vertex.getLabel().get(i).append("String_Node_Str");
    }
  }
  for (int i=startLabel; i < labelCounter; i++) {
    Bucket<VertexIndexPair> bucketV=bucketsV.get(Integer.toString(i));
    for (    VertexIndexPair vp : bucketV.getContents()) {
      vp.getVertex().getLabel().get(vp.getIndex()).append(bucketV.getLabel());
      vp.getVertex().getLabel().get(vp.getIndex()).append("String_Node_Str");
    }
    Bucket<EdgeIndexPair> bucketE=bucketsE.get(Integer.toString(i));
    for (    EdgeIndexPair ep : bucketE.getContents()) {
      ep.getEdge().getLabel().get(ep.getIndex()).append(bucketE.getLabel());
      ep.getEdge().getLabel().get(ep.getIndex()).append("String_Node_Str");
    }
  }
}