public function getIcon(?string $extension): ?string
    {
        $iconClass = $this->iconSet[$this->getIconType($extension)] ?? null;

        return $iconClass !== null
            ? $this->iconPrefix . ' ' . $iconClass
            : null;
    }
public function getIcon(?string $extension): ?string
    {
        $iconClass = $this->iconSet[$this->getIconType($extension)] ?? null;

        return $iconClass !== null
            ? $this->iconPrefix . ' ' . $iconClass
            : null;
    }
public function getIcon ( ? string $ extension ) : ? string { $ iconClass = $ this -> iconSet [ $ this -> getIconType ( $ extension ) ] ?? null ; return $ iconClass !== null ? $ this -> iconPrefix . ' ' . $ iconClass : null ; }
Returns suitable css class for icon by extension.
@param null|string $extension
@return string returns default icon if nothing found
Returns suitable css class for icon by extension .