code: public final void setRestoreDefaultsButtonText(@NonNull final CharSequence text) {
          Condition.INSTANCE.ensureNotNull(text, "The text may not be null");
          Condition.INSTANCE.ensureNotEmpty(text, "The text may not be empty");
          this.restoreDefaultsButtonText = text;
          adaptRestoreDefaultsButtonText();
      }
docs: Sets the text of the button, which allows to restore the preferences' default values. The
  text is only set, if the button is shown.
  
  @param text
  The text, which should be set, as an instance of the class {@link CharSequence}. The
  text may neither be null, nor empty