Liskov

package main

import (
    "fmt"
)

func main() {
    coba := new(CreditCard)
    ProcessPayment(coba,100)
}

type PaymentMethod interface{
    Pay(amount float64)
}

type CreditCard struct{}

func (cc CreditCard) Pay(amount float64){
     fmt.Println("Pay with CC...")
}

func ProcessPayment(method PaymentMethod, amount float64){
    fmt.Println("Processing...")
    method.Pay(amount)
}