#fixed code
                              @GET
  @Path("/result_counter/{identifier}")
  @Produces("application/json")
  public EnumMap<ResultType, Integer> getCounterResults(@PathParam("identifier") String executionIdentifier) {
    try {
      return this.resultCounts.get(executionIdentifier);
    } catch (Exception e) {
      throw new WebException("Could not find any progress to the given identifier",
                             Response.Status.BAD_REQUEST);
    }
  }
#vulnerable code 
                              @GET
  @Path("/result_counter/{identifier}")
  @Produces("application/json")
  public EnumMap<ResultType, Integer> getCounterResults(@PathParam("identifier") String executionIdentifier) {
    try {
      return AlgorithmExecutionCache.getResultCounter(executionIdentifier).getResults();
    } catch (Exception e) {
      throw new WebException("Could not find any progress to the given identifier",
                             Response.Status.BAD_REQUEST);
    }
  } 
                            #location 6 
                            #vulnerability type NULL_DEREFERENCE