You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sleep_perf.go
    path of file: ./repos/azure-sdk-for-go/sdk/internal/perf/testdata/perf
    
    the code of the file until where you have to start completion: // Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License. See License.txt in the project root for license information.

package main

import (
	"context"
	"flag"
	"math"
	"time"

	"github.com/Azure/azure-sdk-for-go/sdk/internal/perf"
)

type sleepTestOptions struct {
	initialDelayMs        int
	instanceGrowthFactor  float64
	
    
func sleepTestRegister() {
	flag.IntVar(&sleepTestOpts.initialDelayMs, "initial-delay-ms", 1000, "Initial delay (in milliseconds)")

	// Used for verifying the perf framework correctly computes average throughput across parallel tests of different speed.
	// Each instance of this test completes operations at a different rate, to allow for testing scenarios where
	// some instances are still waiting when time expires.  The first instance completes in 1 second per operation,
	// the second instance in 2 seconds, the third instance in 4 seconds, and so on.
	flag.Float64Var(&sleepTestOpts.instanceGrowthFactor, "instance-growth-factor", 1, "Instance growth factor.  The delay of instance N will be (InitialDelayMS * (InstanceGrowthFactor ^ InstanceCount)).")

	flag.Float64Var(&sleepTestOpts.iterationGrowthFactor, "iteration-growth-factor", 1, "Iteration growth factor.  The delay of iteration N will be (InitialDelayMS * (IterationGrowthFactor ^ IterationCount)).")
}