* In this case, the failure can be synthetic to provide the stack trace for the problem origin.
     * <p>
     * The failure can also be omitted due to limits. Its absence does not mean there was no exception causing the problem.
     */
    @Nullable
    Failure getFailure();

    /**
     * Returns an exception that can be thrown when this problem should result in an error.
     *

	N := n * hashSize
	var c float64
	// find c such that Prob(mean-c*stddev < x < mean+c*stddev)^N > .9999
	for c = 0.0; math.Pow(math.Erf(c/math.Sqrt(2)), float64(N)) < .9999; c += .1 {
	}
	c *= 11.0 // allowed slack: 40% to 60% - we don't need to be perfectly random
	mean := .5 * REP
	stddev := .5 * math.Sqrt(REP)
	low := int(mean - c*stddev)
	high := int(mean + c*stddev)
	for i := 0; i < n; i++ {

                    cycle.removeLast();
                    stateMap.put(v, DfsState.VISITED);
                } else if (state == DfsState.VISITING) {
                    // we are already visiting this vertex, this mean we have a cycle
                    int pos = cycle.lastIndexOf(v);
                    List<String> ret = cycle.subList(pos, cycle.size());
                    ret.add(v);
                    return ret;
                }

  } else if (type == DT_QINT8) {
    qmin = -128.0;
    qmax = 127.0;
  } else {
    return absl::InvalidArgumentError("Only int8 and uint8 are considered.");
  }
  return std::make_pair((qmin - mean) / std, (qmax - mean) / std);
}

absl::Status RegisterCustomBuiltinOps(
    const std::vector<std::string> extra_tf_opdefs) {
  for (const auto& tf_opdefs_string : extra_tf_opdefs) {
    OpDef opdef;

			snapshot := *v
			req.GetBody = func() (io.ReadCloser, error) {
				r := snapshot
				return io.NopCloser(&r), nil
			}
		default:
			// This is where we'd set it to -1 (at least
			// if body != NoBody) to mean unknown, but
			// that broke people during the Go 1.8 testing
			// period. People depend on it being 0 I
			// guess. Maybe retry later. See Issue 18117.
		}
		// For client requests, Request.ContentLength of 0

      self.base(title, targets, desc)
      + timeSeries.standardOptions.withUnit('s')
      + custom.withDrawStyle('bars')
      + timeSeries.standardOptions.withOverrides([
        fieldOverride.byRegexp.new('/mean/i')
        + fieldOverride.byRegexp.withProperty(
          'custom.fillOpacity',
          0
        )
        + fieldOverride.byRegexp.withProperty(
          'custom.lineStyle',
          {

        def baselineResults = new BaselineVersion(name)
        baselineResults.results.name = name
        def rawResults = results.buildResult(name)
        def shift = rawResults.totalTime.median.value * maxPercentageShift / 100
        baselineResults.results.addAll(rawResults.collect {
            new MeasuredOperation([totalTime: Amount.valueOf(it.totalTime.value + shift, it.totalTime.units), exception: it.exception])

  rewriter.replaceOp(concat_op, output_reshape_op.getResult());

  return success();
}

// ================== mean ========================

// Currently NNAPI does not support mean op with different scales (quantization
// cases), and in TFLite avg_pool will ensure the input & output has the same
// scales.
LogicalResult ReduceMeanToAvgPool::matchAndRewrite(

  // Tries to legalize the specified TensorFlow op, if supported.
  //
  // Emits an error and returns failure if an error is encountered during
  // conversion. Note that success return value doesn't mean successful
  // legalization.
  mlir::LogicalResult LegalizeOp();

  // Converts the given operand to expression of kind kConstant or kXlaOp.
  // Emits a remark and returns expression of kind kInvalid on failure.

                }
                cycle.removeLast();
                stateMap.put(v, DfsState.VISITED);
            } else if (state == DfsState.VISITING) {
                // we are already visiting this vertex, this mean we have a cycle
                int pos = cycle.lastIndexOf(v.label);
                List<String> ret = cycle.subList(pos, cycle.size());
                ret.add(v.label);
                return ret;
            }