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: create_shared_with_helper.go
    path of file: ./repos/golang-samples/compute/instances/custom-machine-type
    
    the code of the file until where you have to start completion: // Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of th
    
func customMachineTypeSharedCoreURI(zone, cpuSeries string, memory int) (string, error) {
	const (
		n1       = "custom"
		n2       = "n2-custom"
		n2d      = "n2d-custom"
		e2       = "e2-custom"
		e2Micro  = "e2-custom-micro"
		e2Small  = "e2-custom-small"
		e2Medium = "e2-custom-medium"
	)

	type typeLimit struct {
		allowedCores     []int
		minMemPerCore    int
		maxMemPerCore    int
		allowExtraMemory bool
		extraMemoryLimit int
	}

	makeRange := func(start, end, step int) []int {
		if step <= 0 || end < start {
			return []int{}
		}
		s := make([]int, 0, 1+(end-start)/step)
		for start <= end {
			s = append(s, start)
			start += step
		}
		return s
	}

	containsString := func(s []string, str string) bool {
		for _, v := range s {
			if v == str {
				return true
			}
		}

		return false
	}

	containsInt := func(nums []int, n int) bool {
		for _, v := range nums {
			if v == n {
				return true
			}
		}

		return false
	}

	var (
		cpuSeriesE2Limit = typeLimit{
			allowedCores:  makeRange(2, 33, 2),
			minMemPerCore: 512,
			maxMemPerCore: 8192,
		}
		cpuSeriesE2MicroLimit  = typeLimit{minMemPerCore: 1024, maxMemPerCore: 2048}
		cpuSeriesE2SmallLimit  = typeLimit{minMemPerCore: 2048, maxMemPerCore: 4096}
		cpuSeriesE2MeidumLimit = typeLimit{minMemPerCore: 4096, maxMemPerCore: 8192}
		cpuSeriesN2Limit       = typeLimit{
			allowedCores:  append(makeRange(2, 33, 2), makeRange(36, 129, 4)...),
			minMemPerCore: 512, maxMemPerCore: 8192,
			allowExtraMemory: true,
			extraMemoryLimit: 624 << 10,
		}
		cpuSeriesN2DLimit = typeLimit{
			allowedCores:  []int{2, 4, 8, 16, 32, 48, 64, 80, 96},
			minMemPerCore: 512, maxMemPerCore: 8192,
			allowExtraMemory: true,
			extraMemoryLimit: 768 << 10,
		}
		cpuSeriesN1Limit = typeLimit{
			allowedCores:     append([]int{1}, makeRange(2, 97, 2)...),
			minMemPerCore:    922,
			maxMemPerCore:    6656,
			allowExtraMemory: true,
			extraMemoryLimit: 624 << 10,
		}
	)

	typeLimitsMap := map[string]typeLimit{
		n1:       cpuSeriesN1Limit,
		n2:       cpuSeriesN2Limit,
		n2d:      cpuSeriesN2DLimit,
		e2:       cpuSeriesE2Limit,
		e2Micro:  cpuSeriesE2MicroLimit,
		e2Small:  cpuSeriesE2SmallLimit,
		e2Medium: cpuSeriesE2MeidumLimit,
	}

	if !containsString([]string{e2Micro, e2Small, e2Medium}, cpuSeries) {
		return "", fmt.Errorf("incorrect cpu type: %v", cpuSeries)
	}

	coreCount := 2
	tl := typeLimitsMap[cpuSeries]

	// Check whether the requested parameters are allowed.
	// Find more information about limitations of custom machine types at:
	// https://cloud.google.com/compute/docs/general-purpose-machines#custom_machine_types

	// Check the number of cores
	if len(tl.allowedCores) > 0 && !containsInt(tl.allowedCores, coreCount) {
		return "", fmt.Errorf(
			"invalid number of cores requested. Allowed number of cores for %v is: %v",
			cpuSeries,
			tl.allowedCores,
		)
	}

	// Memory must be a multiple of 256 MB
	if memory%256 != 0 {
		return "", fmt.Errorf("requested memory must be a multiple of 256 MB")
	}

	// Check if the requested memory isn't too little
	if memory < coreCount*tl.minMemPerCore {
		return "", fmt.Errorf(
			"requested memory is too low. Minimal memory for %v is %v MB per core",
			cpuSeries,
			tl.minMemPerCore,
		)
	}

	// Check if the requested memory isn't too much
	if memory > coreCount*tl.maxMemPerCore && !tl.allowExtraMemory {
		return "", fmt.Errorf(
			"requested memory is too large.. Maximum memory allowed for %v is %v MB per core",
			cpuSeries,
			tl.maxMemPerCore,
		)
	}
	if memory > tl.extraMemoryLimit && tl.allowExtraMemory {
		return "", fmt.Errorf(
			"requested memory is too large.. Maximum memory allowed for %v is %v MB",
			cpuSeries,
			tl.extraMemoryLimit,
		)
	}

	// Return the custom machine type in form of a string acceptable by Compute Engine API.
	if containsString([]string{e2Small, e2Micro, e2Medium}, cpuSeries) {
		return fmt.Sprintf("zones/%v/machineTypes/%v-%v", zone, cpuSeries, memory), nil
	}

	if memory > coreCount*tl.maxMemPerCore {
		return fmt.Sprintf(
			"zones/%v/machineTypes/%v-%v-%v-ext",
			zone,
			cpuSeries,
			coreCount,
			memory,
		), nil
	}

	return fmt.Sprintf("zones/%v/machineTypes/%v-%v-%v", zone, cpuSeries, coreCount, memory), nil
}