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as per listing 6.6 I have used NumCPU() function to find out the number of cpus on my machine. here is my code

package main

import "runtime"
import "fmt"

func main() {

This outputs "4".

but my mac hardware overview displays the below information
processor name: intel core i7
Number of processors: 1
Total number of cores: 2

form where does that 4 come from which is displayed by running that go program.
package main

import "fmt"
import "time"

type SpeedingTicket struct {
DocumentNumber int
IssuingOfficer string
Location string
PostedSpeed int
ActualSpeed int
DateTime time.Time

type Driver struct {
LicenseNumber string
DriverName string
Address string
City string
State string
PostalCode int
LicenseExpiration time.Time

func main() {

tix := SpeedingTicket{
"Speedy Gonzales",
"123 Any Street",
time.Date(2017, time.May, 30, 0, 0, 0, 0, time.UTC),
"Officer D. Duck",
"Intersection of HWY 54 and HWY 41",
time.Date(2013, time.May, 4, 12, 51, 0, 0, time.UTC),



when I execute that I see this message

./types.go:30: cannot use Driver literal (type *Driver) as type Driver in field value

only if I change the embedded type "Driver" in "SpeedingTicket" struct to *Driver it works