/**
  * return a valid style
  * avaible values : "default","primary","success","info","warning","danger"
  * @param string|int $cssStyle
  * @return string
  */
 public static function getStyle($cssStyle, $prefix)
 {
     if (is_int($cssStyle)) {
         $styles = CssRef::Styles($prefix);
         if ($cssStyle < sizeof($styles) && $cssStyle >= 0) {
             return CssRef::styles($prefix)[$cssStyle];
         } else {
             throw new \Exception("La valeur passée a propriété `Style` ne fait pas partie des valeurs possibles : index '" . $cssStyle . "' inexistant");
         }
     }
     if (PhalconUtils::startsWith($cssStyle, "-") === true) {
         $cssStyle = substr($cssStyle, 1);
     }
     if (PhalconUtils::startsWith($cssStyle, $prefix) === false) {
         $cssStyle = $prefix . "-" . $cssStyle;
     }
     return $cssStyle;
 }