Program: 144300
Project: 144300
Buggy source:
/** 
 * Loads vertices and their properties from the csv files
 * @param dir     Directory in which the files reside
 * @param vSet    Set pf expected vertex types
 * @throws IOException              if has trouble reading the file
 * @throws SchemaViolationException if file doesn't match the expected schema according to the workload definition
 */
private void loadVertices(File dir,Set<String> vSet) throws IOException, SchemaViolationException {
  logger.info("String_Node_Str");
  WorkLoadSchema s=this.workload.getSchema();
  for (  final String vLabel : vSet) {
    HashSet<String> fileSet=new HashSet<>();
    fileSet.addAll(Arrays.asList(dir.list(new FilenameFilter(){
      @Override public boolean accept(      File dir,      String name){
        return name.matches(vLabel.toLowerCase() + "String_Node_Str");
      }
    }
)));
    for (    String fName : fileSet) {
      logger.info("String_Node_Str",fName);
      File csvFile=new File(dir,fName);
      BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream(csvFile),Charset.forName("String_Node_Str")));
      String line=br.readLine();
      if (line == null)       throw new IOException("String_Node_Str" + fName);
      String[] header=line.split(CSVSPLIT);
      short suffix;
      try {
        validateVHeader(s,vLabel,header);
      }
 catch (      SchemaViolationException e) {
        br.close();
        throw e;
      }
      int rowLength=header.length;
      logger.info("String_Node_Str" + rowLength);
      String[] classNames=new String[rowLength];
      for (int i=0; i < rowLength; i++) {
        String prop=header[i];
        logger.info("String_Node_Str" + prop);
        Class clazz=s.getVPropertyClass(vLabel,prop);
        classNames[i]=clazz.getSimpleName();
      }
      try {
        int counter=0;
        while ((line=br.readLine()) != null) {
          if (counter % 100 == 0) {
            logger.info("String_Node_Str" + vLabel + "String_Node_Str"+ counter);
          }
          String[] row=line.split(CSVSPLIT);
          JanusGraphVertex vertex=graph.addVertex(vLabel);
          for (int i=0; i < row.length; ++i) {
            String prop=header[i];
            Object value=parseEntry(row[i],classNames[i]);
            vertex.property(vLabel + "String_Node_Str" + prop,value);
          }
          counter++;
        }
      }
 catch (      Exception e) {
        System.err.println("String_Node_Str");
        e.printStackTrace();
        graph.close();
      }
 finally {
        br.close();
      }
    }
    logger.info("String_Node_Str",vLabel);
  }
  logger.info("String_Node_Str");
}

Fixed version (ground truth):
/** 
 * Loads vertices and their properties from the csv files
 * @param dir     Directory in which the files reside
 * @param vSet    Set pf expected vertex types
 * @throws IOException              if has trouble reading the file
 * @throws SchemaViolationException if file doesn't match the expected schema according to the workload definition
 */
private void loadVertices(File dir,Set<String> vSet) throws IOException, SchemaViolationException {
  logger.info("String_Node_Str");
  WorkLoadSchema s=this.workload.getSchema();
  for (  final String vLabel : vSet) {
    HashSet<String> fileSet=new HashSet<>();
    fileSet.addAll(Arrays.asList(dir.list(new FilenameFilter(){
      @Override public boolean accept(      File dir,      String name){
        return name.matches(vLabel.toLowerCase() + "String_Node_Str");
      }
    }
)));
    for (    String fName : fileSet) {
      logger.info("String_Node_Str",fName);
      File csvFile=new File(dir,fName);
      BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream(csvFile),Charset.forName("String_Node_Str")));
      String line=br.readLine();
      if (line == null)       throw new IOException("String_Node_Str" + fName);
      String[] header=line.split(CSVSPLIT);
      try {
        validateVHeader(s,vLabel,header);
      }
 catch (      SchemaViolationException e) {
        br.close();
        throw e;
      }
      int rowLength=header.length;
      logger.info("String_Node_Str" + rowLength);
      String[] classNames=new String[rowLength];
      for (int i=0; i < rowLength; i++) {
        String prop=header[i];
        logger.info("String_Node_Str" + prop);
        Class clazz=s.getVPropertyClass(vLabel,prop);
        classNames[i]=clazz.getSimpleName();
      }
      try {
        int counter=0;
        while ((line=br.readLine()) != null) {
          if (counter % 100 == 0) {
            logger.info("String_Node_Str" + vLabel + "String_Node_Str"+ counter);
          }
          String[] row=line.split(CSVSPLIT);
          JanusGraphVertex vertex=graph.addVertex(vLabel);
          for (int i=0; i < row.length; ++i) {
            String prop=header[i];
            Object value=parseEntry(row[i],classNames[i]);
            vertex.property(vLabel + "String_Node_Str" + prop,value);
          }
          counter++;
        }
      }
 catch (      Exception e) {
        System.err.println("String_Node_Str");
        e.printStackTrace();
        graph.close();
      }
 finally {
        br.close();
      }
    }
    logger.info("String_Node_Str",vLabel);
  }
  logger.info("String_Node_Str");
}