BasePresenter_processServerException.kt

...

private fun processServerException(exception: ServerException) {
    viewState.showError(exception.description)

    when (exception.code) {
        ErrorCode.INVALID_CREDENTIALS -> invalidCredentialsCallback()
        ErrorCode.AUTHENTICATION_REQUIRED -> authenticationRequiredCallback()
        ErrorCode.UNKNOWN -> unknownServerErrorCallback()
    }
}

...

open fun invalidCredentialsCallback() {}
open fun authenticationRequiredCallback() {}
open fun unknownServerErrorCallback() {}

...