public function renderElementFormGroup($sElementContent, $sRowClass, $sFeedbackElement = '' )
    {
        if (!is_string($sElementContent)) {
            throw new \InvalidArgumentException('Argument "$sElementContent" expects a string, "' . (is_object($sElementContent) ? get_class($sElementContent) : gettype($sElementContent)) . '" given');
        }
        if (!is_string($sRowClass)) {
            throw new \InvalidArgumentException('Argument "$sRowClass" expects a string, "' . (is_object($sRowClass) ? get_class($sRowClass) : gettype($sRowClass)) . '" given');
        }
        if ($sFeedbackElement && !is_string($sFeedbackElement)) {
            throw new \InvalidArgumentException('Argument "$sFeedbackElement" expects a string, "' . (is_object($sFeedbackElement) ? get_class($sFeedbackElement) : gettype($sFeedbackElement)) . '" given');
        }
        if( $sFeedbackElement ){
            $sElementContent .= '<i class="' . $sFeedbackElement . ' form-control-feedback"></i>';
        }
        return sprintf(static::$formGroupFormat, $sRowClass, $sElementContent) . "\n";
    }
public function renderElementFormGroup($sElementContent, $sRowClass, $sFeedbackElement = '' )
    {
        if (!is_string($sElementContent)) {
            throw new \InvalidArgumentException('Argument "$sElementContent" expects a string, "' . (is_object($sElementContent) ? get_class($sElementContent) : gettype($sElementContent)) . '" given');
        }
        if (!is_string($sRowClass)) {
            throw new \InvalidArgumentException('Argument "$sRowClass" expects a string, "' . (is_object($sRowClass) ? get_class($sRowClass) : gettype($sRowClass)) . '" given');
        }
        if ($sFeedbackElement && !is_string($sFeedbackElement)) {
            throw new \InvalidArgumentException('Argument "$sFeedbackElement" expects a string, "' . (is_object($sFeedbackElement) ? get_class($sFeedbackElement) : gettype($sFeedbackElement)) . '" given');
        }
        if( $sFeedbackElement ){
            $sElementContent .= '<i class="' . $sFeedbackElement . ' form-control-feedback"></i>';
        }
        return sprintf(static::$formGroupFormat, $sRowClass, $sElementContent) . "\n";
    }
@param string $sElementContent
@param string $sRowClass
@param string $sFeedbackElement A feedback element that should be rendered within the element, optional

@return string
@throws \InvalidArgumentException