code: protected void onSelectedInstantChanged() {
          if (selectedInstant == null) {
              getInputWidget().setText("");
              anchorLabel();
          } else {
              getInputWidget().setText(getInstantPrinter().print(selectedInstant));
              floatLabel();
          }
  
          if (instantPickerListener != null)
              instantPickerListener.onInstantChanged(this, selectedInstant);
      }
docs: Refreshes the widget state when the selection changes