Prototype Design Pattern example in Go (GoLang).

prototype.go

package main

import "fmt"

/*
In go, primitive types, and structs containing only primitive types, are copied by value.
You can copy them by simply assigning to a new variable (or returning from a function).
If your struct happens to include arrays, slices, or pointers, then you'll need to perform a deep copy of the referenced objects
unless you want to retain references between copies.
Source: https://stackoverflow.com/questions/51635766/how-do-i-copy-a-struct
This means you don't need the prototype patterns in most cases.
If you need it, just make a method to deepcopy the "prototype".
You can do it yourself or use any pkg like https://github.com/jinzhu/copier
*/

type Person struct {
	Name           string
	Age            int
	Mother, Father *Person
}

func (p *Person) String() string {
	str := fmt.Sprintf("%s (%v)", p.Name, p.Age)
	if p.Mother != nil || p.Father != nil {
		str += " son of "
		if p.Mother != nil {
			str += p.Mother.Name
		}
		if p.Mother != nil && p.Father != nil {
			str += " and "
		}
		if p.Father != nil {
			str += p.Father.Name
		}
	}
	return str
}

func main() {
	mom := Person{"Mariette", 51, nil, nil}
	dad := Person{"Andre", 55, nil, nil}

	max := Person{"Maxime", 30, &mom, &dad}
	fmt.Printf("max: %s\n\n", &max)

	brother := max
	brother.Name = "Robert"
	fmt.Printf("bob (copied from max and changing name): %s\n", &brother)
	fmt.Printf("max (after changing the name of bob): %s\n\n", &max)

	brother.Mother.Name = "Antoinette"
	fmt.Printf("bob (after changing name of her mother): %s\n", &brother)
	fmt.Printf("max (after changing the name of the mother of bob): %s\n\n", &max)

	brother.Mother = &Person{"Denise", 57, nil, nil}
	fmt.Printf("bob (after changing mother pointer): %s\n", &brother)
	fmt.Printf("max (after changing mother pointer of bob): %s\n", &max)
}

This will print:

max: Maxime (30) son of Mariette and Andre

bob (copied from max and changing name): Robert (30) son of Mariette and Andre
max (after changing the name of bob): Maxime (30) son of Mariette and Andre

bob (after changing name of her mother): Robert (30) son of Antoinette and Andre
max (after changing the name of the mother of bob): Maxime (30) son of Antoinette and Andre

bob (after changing mother pointer): Robert (30) son of Denise and Andre
max (after changing mother pointer of bob): Maxime (30) son of Antoinette and Andre