The example below shows a class that contains the logic of a feature in an app where a user can invite another user based on certain internal conditions.

FriendReferral.kt

fun referFriend(userId: String, referral: Referral) {
   if (isReferralValid(referral)) {
      processReferral(userId)
   }
}

private fun isReferralValid(referral: Referral): Boolean {
  // Checks the validity of the referral.
}

private fun processReferral(userId: String) {
 // Processes the referral.
}