code: public final void addItem(@Nullable final CharSequence title,
                                @NonNull final Class<? extends Fragment> fragmentClass,
                                @Nullable final Bundle arguments) {
          Condition.INSTANCE.ensureNotNull(fragmentClass, "The fragment class may not be null");
          items.add(new ViewPagerItem(title, fragmentClass, arguments));
          notifyDataSetChanged();
      }
docs: Adds a new fragment to the adapter.
  
  @param title
  The title of the fragment, which should be added, as an instance of the type {@link
  CharSequence} or null, if no title should be set
  @param fragmentClass
  The class of the fragment, which should be added, as an instance of the class {@link
  Class}. The class may not be null
  @param arguments
  A bundle, which should be passed to the fragment, when it is shown, as an instance of
  the class {@link Bundle} or null, if no arguments should be passed to the fragment