code: private void adaptButtonTypeface() {
          if (buttonTypeface != null) {
              if (positiveButton != null) {
                  positiveButton.setTypeface(buttonTypeface);
              }
  
              if (neutralButton != null) {
                  neutralButton.setTypeface(buttonTypeface);
              }
  
              if (negativeButton != null) {
                  negativeButton.setTypeface(buttonTypeface);
              }
          }
      }
docs: Adapts the typeface of the dialog's buttons.