Email check state

EmailCheckState.kt

class EmailCheckState(
    context: WelcomeContext,
    private val data: WelcomeDataState,
    private val checkEmail: CheckEmail
) : WelcomeState(context) {

    private val email = requireNotNull(data.email) {
        "Email is not provided"
    }

   override fun doStart() {
        setUiState(renderer.renderChecking(data))
        stateScope.launch {
            val exists = checkEmail(email)
            if (exists) {
                setMachineState(factory.loginFlow(data))
            } else {
                setMachineState(factory.registrationFlow(data))
            }
        }
    }
}