### Question:
FirebaseInAppMessaging { public void addDisplayErrorListener( @NonNull FirebaseInAppMessagingDisplayErrorListener displayErrorListener) { developerListenerManager.addDisplayErrorListener(displayErrorListener); } @VisibleForTesting @Inject  FirebaseInAppMessaging(
      InAppMessageStreamManager inAppMessageStreamManager,
      @ProgrammaticTrigger ProgramaticContextualTriggers programaticContextualTriggers,
      DataCollectionHelper dataCollectionHelper,
      FirebaseInstallationsApi firebaseInstallations,
      DisplayCallbacksFactory displayCallbacksFactory,
      DeveloperListenerManager developerListenerManager); @NonNull static FirebaseInAppMessaging getInstance(); boolean isAutomaticDataCollectionEnabled(); void setAutomaticDataCollectionEnabled(@Nullable Boolean isAutomaticCollectionEnabled); void setAutomaticDataCollectionEnabled(boolean isAutomaticCollectionEnabled); void setMessagesSuppressed(@NonNull Boolean areMessagesSuppressed); boolean areMessagesSuppressed(); void setMessageDisplayComponent(@NonNull FirebaseInAppMessagingDisplay messageDisplay); void clearDisplayListener(); void addImpressionListener(
      @NonNull FirebaseInAppMessagingImpressionListener impressionListener); void addClickListener(@NonNull FirebaseInAppMessagingClickListener clickListener); void addDismissListener(@NonNull FirebaseInAppMessagingDismissListener dismissListener); void addDisplayErrorListener(
      @NonNull FirebaseInAppMessagingDisplayErrorListener displayErrorListener); void addImpressionListener(
      @NonNull FirebaseInAppMessagingImpressionListener impressionListener,
      @NonNull Executor executor); void addClickListener(
      @NonNull FirebaseInAppMessagingClickListener clickListener, @NonNull Executor executor); void addDismissListener(
      @NonNull FirebaseInAppMessagingDismissListener dismissListener, @NonNull Executor executor); void addDisplayErrorListener(
      @NonNull FirebaseInAppMessagingDisplayErrorListener displayErrorListener,
      @NonNull Executor executor); void removeImpressionListener(
      @NonNull FirebaseInAppMessagingImpressionListener impressionListener); void removeClickListener(@NonNull FirebaseInAppMessagingClickListener clickListener); void removeDisplayErrorListener(
      @NonNull FirebaseInAppMessagingDisplayErrorListener displayErrorListener); void removeAllListeners(); void triggerEvent(@NonNull String eventName);  }### Answer:
@Test public void addDisplayErrorListener_forwardsEventListenerRequestsToDeveloperListenerManager() { firebaseInAppMessaging.addDisplayErrorListener((inAppMessage, error) -> {}); verify(developerListenerManager, times(1)).addDisplayErrorListener(any()); }