code: private Preference.OnPreferenceChangeListener createShowValueAsSummaryListener() {
          return new Preference.OnPreferenceChangeListener() {
  
              @Override
              public boolean onPreferenceChange(final Preference preference, final Object newValue) {
                  boolean showValueAsSummary = (Boolean) newValue;
                  editTextPreference.showValueAsSummary(showValueAsSummary);
                  listPreference.showValueAsSummary(showValueAsSummary);
                  multiChoiceListPreference.showValueAsSummary(showValueAsSummary);
                  seekBarPreference.showValueAsSummary(showValueAsSummary);
                  numberPickerPreference.showValueAsSummary(showValueAsSummary);
                  digitPickerPreference.showValueAsSummary(showValueAsSummary);
                  resolutionPreference.showValueAsSummary(showValueAsSummary);
                  colorPalettePreference.showValueAsSummary(showValueAsSummary);
                  adaptSwitchPreferenceSummary(showValueAsSummary);
                  return true;
              }
  
          };
      }
docs: Creates and returns a listener, which allows to adapt, whether the preference's values should
  be shown as summaries, or not, when the corresponding setting has been changed.
  
  @return The listener, which has been created, as an instance of the type {@link
  Preference.OnPreferenceChangeListener}