code: public function getFontIconClassNames()
      {
          $classes = [];
          
          if ($this->owner->FontIcon) {
              
              if ($this->owner->FontIconListItem) {
                  $classes[] = $this->backend->getClassName('list-item');
              }
              
              if ($this->owner->FontIconFixedWidth) {
                  $classes[] = $this->backend->getClassName('fixed-width');
              }
              
              $classes[] = $this->backend->getClassName('icon', [$this->owner->FontIcon]);
              
          }
          
          return $classes;
      }
docs: Answers an array of font icon class names for the extended object.
  
  @return array