code: private ViewPropertyAnimator createAnimator(@NonNull final View animatedView,
                                                  @NonNull final FadeAnimation animation,
                                                  @Nullable final AnimatorListener listener,
                                                  final boolean show) {
          if (animation.getAlpha() != null) {
              ViewPropertyAnimator animator =
                      animatedView.animate().setInterpolator(animation.getInterpolator())
                              .setDuration(getDuration(animatedView, animation))
                              .setStartDelay(animation.getStartDelay()).setListener(listener);
  
              if (show) {
                  animatedView.setAlpha(animation.getAlpha());
                  animator.alpha(1);
              } else {
                  animatedView.setAlpha(1f);
                  animator.alpha(animation.getAlpha());
              }
  
              return animator;
          }
  
          return null;
      }
docs: Creates an animator, which should be used for a fade animation.
  
  @param animatedView
  The animated view as an instance of the class {@link View}. The view may not be null
  @param animation
  The animation as an instance of the class {@link FadeAnimation}. The animation may
  not be null
  @param listener
  The listener, which should be notified about the animation's events, as an instance
  of the type {@link AnimatorListener} or null, if no listener should be notified
  @param show
  True, if the animation should be used to show the dialog, false otherwise
  @return The animator, which has been created, as an instance of the class {@link
  ViewPropertyAnimator} or null, if no animation should be used