# friend_of.ludic — L3: `friend module lab of bank` sees bank's private names and no other module's;
# a test harness reaches inside exactly what it tests. `friend module lab` alone still sees all.
#
# Running it prints:  7 7
import "bank"
program FriendOf {
  friend module lab of bank
  entry (bank_st: mut BankState) {
    add(bank_st, 7)
    print(`{bank_st.balance} {total(bank_st)}`)
  }
}