output: #fixed code
                               public DuplicateResult findDuplicates(State state)
  	{
  		DuplicateResult result = new DuplicateResult(parameters);
  
  		List<FileState> fileStates = new ArrayList<>(state.getFileStates());
  		Collections.sort(fileStates, hashComparator);
  
  		List<FileState> duplicatedFiles = new ArrayList<>();
  		FileHash previousFileHash = new FileHash(FileState.NO_HASH, FileState.NO_HASH, FileState.NO_HASH);
  		for (FileState fileState : fileStates)
  		{
  			if (!previousFileHash.equals(fileState.getFileHash()))
  			{
  				result.addDuplicatedFiles(duplicatedFiles);
  				duplicatedFiles.clear();
  			}
  
  			previousFileHash = fileState.getFileHash();
  			duplicatedFiles.add(fileState);
  		}
  		result.addDuplicatedFiles(duplicatedFiles);
  
  		return result;
  	}
input: #vulnerable code 
                               public DuplicateResult findDuplicates(State state)
  	{
  		DuplicateResult result = new DuplicateResult(parameters);
  
  		List<FileState> fileStates = new ArrayList<>(state.getFileStates());
  		Collections.sort(fileStates, fullHashComparator);
  
  		FileHash previousHash = new FileHash(FileState.NO_HASH, FileState.NO_HASH, FileState.NO_HASH);
  		for (FileState fileState : fileStates)
  		{
  			if (!previousHash.equals(fileState.getFileHash()))
  			{
  				result.addDuplicatedFiles(duplicatedFiles);
  				duplicatedFiles.clear();
  			}
  
  			previousHash = fileState.getFileHash();
  			duplicatedFiles.add(fileState);
  		}
  		result.addDuplicatedFiles(duplicatedFiles);
  
  		return result;
  	} 
                              #location 11 
                              #vulnerability type NULL_DEREFERENCE