/**
  * define the button style
  * avaible values : "btn-default","btn-primary","btn-success","btn-info","btn-warning","btn-danger"
  * @param string|int $cssStyle
  * @return \Ajax\bootstrap\html\HtmlDropdown default : "btn-default"
  */
 public function setStyle($cssStyle)
 {
     if (is_int($cssStyle)) {
         return $this->addToMember($this->class, CssRef::buttonStyles()[$cssStyle]);
     }
     if (PhalconUtils::startsWith($cssStyle, "btn-") === false) {
         $cssStyle = "btn" . $cssStyle;
     }
     return $this->addToMemberCtrl($this->class, $cssStyle, CssRef::buttonStyles());
 }