Issue #3300739 by e0ipso: Defer setting default form values to the form generator library

      'ui_hints' => $widget_type->getFormSchema(),

      'form_state' => $form_state,

      'form' => $form,

      'current_input' => $widget_instance->getDisplayOptions(),

    ]);

    $display_options = NestedArray::mergeDeep(

      $display_options,

      $this->formGenerator->transform($schema, $context)

    );

    foreach ($widget_instance->getDisplayOptions() as $key => $value) {

      NestedArray::setValue($display_options, [$key, '#default_value'], $value);

    }

  }

  /**