liskovtest.swift

class test{
    //takes package parent class
    init(package: Package,price :Int64) {
        do{
            try 8 * 100/package.setPrice(price:price)
            print("done")
        }catch {
            print("price value must be greater than 0 _ \(price) ")
        }
       
    }
}
test(package: Package(),price: 10) //no issues

test(package: Pro(),price: 999) //error //strentened pre conds

test(package: Basic(),price: 999) //error //strentened pre conds

test(package: Basic(),price: 999) //error //weakened post condition