Android 8 getAccounts

Question

How do I get accounts on Android Oreo? I went through "Account access and discoverability" in documentation:

https://developer.android.com/about/versions/oreo/android-8.0-changes.html

but it is a ZERO help, and there are also no examples or at least something i can start with...

I always use this approach (after granted permission GET_ACCOUNTS from user):

        val mUserList = arrayListOf<String>()
        val accountManager = getSystemService(Context.ACCOUNT_SERVICE) as AccountManager
        val accounts = accountManager.accounts
        accounts
                .filter {
                    !mUserList.contains(it.name) &&
                            it.name.contains("google.com") ||
                            it.name.contains("example.domain")
                }.map { mUserList.add(it.name) }

This is working on any API except 26 and 27.

So I'm traversing trough all the accounts (accountManager.accounts) and filtering only the domains I need and put them in a list, then I send that list to a custom dialog where user can pick which one he wants, and that leads him to a password dialog, plain and simple.

How do I do that for Oreo, and will it be backward compatible?