}
        1 * progressListener.started({it.description == "op-2"}) >> { ProgressStartEvent event ->
            id2 = event.progressOperationId
            assert event.parentProgressOperationId == null
        }

        and:
        [parentId, childId, id2].toSet().size() == 3
    }

    def "operation can have parent running in a different thread"() {
        OperationIdentifier parentId

    });

class CustomAggregatorOp : public OpKernel {
 public:
  explicit CustomAggregatorOp(OpKernelConstruction* context)
      : OpKernel(context) {
    OP_REQUIRES_OK(context, context->GetAttr("id", &id_));

    int calibration_method_value;
    int num_bins;
    float min_percentile;
    float max_percentile;
    OP_REQUIRES_OK(context, context->GetAttr("calibration_method",

	SYS_CPUSET_SETID             = 485 // { int cpuset_setid(cpuwhich_t which, id_t id, cpusetid_t setid); }
	SYS_CPUSET_GETID             = 486 // { int cpuset_getid(cpulevel_t level, cpuwhich_t which, id_t id, cpusetid_t *setid); }
	SYS_CPUSET_GETAFFINITY       = 487 // { int cpuset_getaffinity(cpulevel_t level, cpuwhich_t which, id_t id, size_t cpusetsize, cpuset_t *mask); }

            assert operation.id == id2
            assert context.failure == null
        }
    }

    def "multiple threads can run child operations concurrently"() {
        setup:
        BuildOperationRef parent
        def id1
        def id2

        when:
        operationRunner.run(runnableBuildOperation("<main>") {

	SYS_FSYNC                = 95  // { int|sys||fsync(int fd); }
	SYS_SETPRIORITY          = 96  // { int|sys||setpriority(int which, id_t who, int prio); }
	SYS_CONNECT              = 98  // { int|sys||connect(int s, const struct sockaddr *name, socklen_t namelen); }
	SYS_GETPRIORITY          = 100 // { int|sys||getpriority(int which, id_t who); }
	SYS_BIND                 = 104 // { int|sys||bind(int s, const struct sockaddr *name, socklen_t namelen); }

	SYS_FSYNC                = 95  // { int|sys||fsync(int fd); }
	SYS_SETPRIORITY          = 96  // { int|sys||setpriority(int which, id_t who, int prio); }
	SYS_CONNECT              = 98  // { int|sys||connect(int s, const struct sockaddr *name, socklen_t namelen); }
	SYS_GETPRIORITY          = 100 // { int|sys||getpriority(int which, id_t who); }
	SYS_BIND                 = 104 // { int|sys||bind(int s, const struct sockaddr *name, socklen_t namelen); }

                         std::vector<Output>* grad_outputs) {
  // Running example:
  // indices = {2, [1, 0]}
  // data = {[d_1, d_2], [[d_3, d_4], [d_5, d_6]]}
  // out = [[d_5, d_6], [d_3, d_4], [d_1, d_2]]
  // grad = [[g_1, g_2], [g_3, g_4], [g_5, g_6]]

  // indices and data are two equal-sized lists passed
  // into DynamicStitch.
  // num_values = 2

	SYS_FFCLOCK_SETESTIMATE      = 242 // { int ffclock_setestimate( \
	SYS_FFCLOCK_GETESTIMATE      = 243 // { int ffclock_getestimate( \
	SYS_CLOCK_GETCPUCLOCKID2     = 247 // { int clock_getcpuclockid2(id_t id,\
	SYS_NTP_GETTIME              = 248 // { int ntp_gettime(struct ntptimeval *ntvp); }
	SYS_MINHERIT                 = 250 // { int minherit(void *addr, size_t len, \

minio server --config-dir /tmp/minio-internal --address ":9002" http://localhost:9002/tmp/minio-internal-idp2/{1...4} http://localhost:9020/tmp/minio-internal-idp2/{5...8} >/tmp/minio2_1.log 2>&1 &
site2_pid1=$!
minio server --config-dir /tmp/minio-internal --address ":9020" http://localhost:9002/tmp/minio-internal-idp2/{1...4} http://localhost:9020/tmp/minio-internal-idp2/{5...8} >/tmp/minio2_2.log 2>&1 &
site2_pid2=$!

	SYS_FFCLOCK_SETESTIMATE      = 242 // { int ffclock_setestimate( \
	SYS_FFCLOCK_GETESTIMATE      = 243 // { int ffclock_getestimate( \
	SYS_CLOCK_GETCPUCLOCKID2     = 247 // { int clock_getcpuclockid2(id_t id,\
	SYS_NTP_GETTIME              = 248 // { int ntp_gettime(struct ntptimeval *ntvp); }
	SYS_MINHERIT                 = 250 // { int minherit(void *addr, size_t len, \