https://api.drupal.org/api/drupal/core%21modules%21link%21src%21Plugin%21Field%21FieldWidget%21LinkWidget.php/9
LinkWidget.php | Drupal API
phpdrupalapi
https://api.drupal.org/api/drupal/core%21modules%21link%21src%21Plugin%21Field%21FieldWidget%21LinkWidget.php/function/LinkWidget%3A%3AgetUserEnteredStringAsUri/8.9.x
function LinkWidget::getUserEnteredStringAsUri | Drupal API
functiondrupalapi