anchor.diff:                  } catch (IOException ignored) {}
               }
           }
  +
           done.run(response);
       }
   }
  
positive.code: //HConnection connection = HConnectionManager.createConnection(conf);
  //HTableInterface table = connection.getTable("users");
  
  final SumRequest request = SumRequest.newBuilder().setFamily("salaryDet").setColumn("gross")
                              .build();
  try {
  Map<byte[], Long> results = table.CoprocessorService (SumService.class, null, null,
  new Batch.Call<SumService, Long>() {
      @Override
          public Long call(SumService aggregate) throws IOException {
  BlockingRpcCallback rpcCallback = new BlockingRpcCallback();
              aggregate.getSum(null, request, rpcCallback);
              SumResponse response = rpcCallback.get();
              return response.hasSum() ? response.getSum() : 0L;
          }
      });
      for (Long sum : results.values()) {
          System.out.println("Sum = " + sum);
      }
  } catch (ServiceException e) {
  e.printStackTrace();
  } catch (Throwable e) {
      e.printStackTrace();
  }
  
negative.code: +
  [source, java]
  ----
  public class SumEndPoint extends Sum.SumService implements Coprocessor, CoprocessorService {
  
      private RegionCoprocessorEnvironment env;
  
  