code: protected function getWithDefault($field)
      {
          $value = $this->owner->getField($field);
          if ($value) {
              return $value;
          }
          // fallback to default value
          $defaults = $this->owner->config()->get('defaults');
          if (isset($defaults[$field])) {
              return $defaults[$field];
          }
      }
docs: Get the value of a user-configured field, falling back to the default if left blank.
  
  @param string $field
  
  @return string