Only 1 AndroidEntryPoint and use ActivityRetainedScoped

CodeGen.java

private EmailSender getEmailSender() {
          Object local = emailSender;
          if (local instanceof MemoizedSentinel) {
            synchronized (local) {
              local = emailSender;
              if (local instanceof MemoizedSentinel) {
                local = new EmailSender();
                emailSender = DoubleCheck.reentrantCheck(emailSender, local);
              }
            }
          }
          return (EmailSender) local;
        }

        private ClassA getClassA() {
          return new ClassA(getEmailSender());}

        private ClassB getClassB() {
          return new ClassB(getEmailSender());}

InjectableStuff.kt

@ActivityRetainedScoped
class EmailSender @Inject constructor() {
    fun send(msg: String){
        println(msg)
    }
}


class ClassA 
@Inject constructor(
    private val emailSender: EmailSender
) {
    init {
        println("From $this EmailSender is $emailSender")
    }
}
class ClassB @Inject constructor(
    private val emailSender: EmailSender
) {
    init {
        println("From $this EmailSender is $emailSender")
    }
}

MainFragment.kt

@AndroidEntryPoint
class MainFragment : Fragment() {
    @Inject
    lateinit var emailSender: EmailSender
    @Inject
    lateinit var classA: ClassA
    @Inject
    lateinit var classB: ClassB
 override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        println("From $this EmailSender is $emailSender")
    }

RESULT

2021-01-05 10:33:21.296 13089-13089 From ClassA@5d9e5b2 EmailSender is EmailSender@b6f3903
2021-01-05 10:33:21.296 13089-13089 From ClassB@d0c6080 EmailSender is EmailSender@b6f3903
2021-01-05 10:33:21.362 13089-13089 From MainFragment{fa313f1}  EmailSender is EmailSender@b6f3903