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: architecture_windows.go
    path of file: ./repos/docker-ce/components/engine/pkg/platform
    
    the code of the file until where you have to start completion: package platform // import "github.com/docker/docker/pkg/platform"

import (
	"fmt"
	"syscall"
	"unsafe"

	"golang.org/x/sys/windows"
)

var (
	modkernel32       = windows.NewLazySystemDLL("kernel32.dll")
	procGetSystemInfo = modkernel32.NewProc("GetSyste
    
func runtimeArchitecture() (string, error) {
	var sysinfo systeminfo
	syscall.Syscall(procGetSystemInfo.Addr(), 1, uintptr(unsafe.Pointer(&sysinfo)), 0, 0)
	switch sysinfo.wProcessorArchitecture {
	case ProcessorArchitecture64, ProcessorArchitectureIA64:
		return "x86_64", nil
	case ProcessorArchitecture32:
		return "i686", nil
	case ProcessorArchitectureArm:
		return "arm", nil
	default:
		return "", fmt.Errorf("Unknown processor architecture")
	}
}