title: Unresolvered reference: when I call the method of an instance from another activity
body: <p>I would like to call the method of an instance of AuthActivity from MainActivity. However, I get an error.
  AuthActivity contains a variable that lets you know if the user has already authenticated from this activity!</p>
  <p>Unresolvered reference: checkIfUserAlreadyLogged()</p>
  <pre><code>class MainActivity : AppCompatActivity() {
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
          FirebaseApp.initializeApp(applicationContext)
          setContentView(R.layout.activity_main)
  
        
          if (AuthActivity.checkIfUserAlreadyLogged()) {
              return this.displayAuthWithFragment(AuthActivity.HOME_FRAGMENT)
          }
  
      }
   }
  </code></pre>
  <p>Here is my AuthActivity class:</p>
  <pre><code>package com.ksainthi.inance
  
  
  import androidx.appcompat.app.AppCompatActivity
  import androidx.activity.result.contract.ActivityResultContracts
  import androidx.fragment.app.Fragment
  import com.google.firebase.auth.FirebaseAuth
  
  class AuthActivity : AppCompatActivity() {
  
      private val firebaseAuth: FirebaseAuth by lazy {
          FirebaseAuth.getInstance()
      }
  
  
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
          setContentView(R.layout.activity_auth)
  
      }
  
  
      fun checkIfUserAlreadyLogged(): Boolean {
          if (this.firebaseAuth.currentUser != null) {
              return true
          }
          return false
      }
   }
   
  </code></pre>