src/Debug/Output/Html.php
protected function buildGroupMethod($method, $args = array(), $meta = array())
    {
        $str = '';
        if (\in_array($method, array('group','groupCollapsed'))) {
            $label = \array_shift($args);
            $levelClass = isset($meta['level'])
                ? 'level-'.$meta['level']
                : null;
            if (!empty($meta['isMethodName'])) {
                $label = $this->markupClassname($label);
            }
            foreach ($args as $k => $v) {
                $args[$k] = $this->dump($v);
            }
            $argStr = \implode(', ', $args);
            /*
                Header
            */
            $str .= $this->debug->utilities->buildTag(
                'div',
                array(
                    'class' => array(
                        'group-header',
                        $method == 'groupCollapsed'
                            ? 'collapsed'
                            : 'expanded',
                        $levelClass,
                    ),
                    'data-channel' => $meta['channel'],
                ),
                '<span class="group-label">'
                    .$label
                    .(!empty($argStr)
                        ? '(</span>'.$argStr.'<span class="group-label">)'
                        : '')
                .'</span>'
            )."\n";
            /*
                Group open
            */
            $str .= '<div'.$this->debug->utilities->buildAttribString(array(
                'class' => array(
                    'm_group',
                    $levelClass,
                ),
            )).'>';
        } elseif ($method == 'groupEnd') {
            $str = '</div>';
        }
        return $str;
    }
protected function buildGroupMethod($method, $args = array(), $meta = array())
    {
        $str = '';
        if (\in_array($method, array('group','groupCollapsed'))) {
            $label = \array_shift($args);
            $levelClass = isset($meta['level'])
                ? 'level-'.$meta['level']
                : null;
            if (!empty($meta['isMethodName'])) {
                $label = $this->markupClassname($label);
            }
            foreach ($args as $k => $v) {
                $args[$k] = $this->dump($v);
            }
            $argStr = \implode(', ', $args);
            /*
                Header
            */
            $str .= $this->debug->utilities->buildTag(
                'div',
                array(
                    'class' => array(
                        'group-header',
                        $method == 'groupCollapsed'
                            ? 'collapsed'
                            : 'expanded',
                        $levelClass,
                    ),
                    'data-channel' => $meta['channel'],
                ),
                '<span class="group-label">'
                    .$label
                    .(!empty($argStr)
                        ? '(</span>'.$argStr.'<span class="group-label">)'
                        : '')
                .'</span>'
            )."\n";
            /*
                Group open
            */
            $str .= '<div'.$this->debug->utilities->buildAttribString(array(
                'class' => array(
                    'm_group',
                    $levelClass,
                ),
            )).'>';
        } elseif ($method == 'groupEnd') {
            $str = '</div>';
        }
        return $str;
    }
handle html output of group, groupCollapsed, & groupEnd

@param string $method group|groupCollapsed|groupEnd
@param array  $args   args passed to method
@param array  $meta   meta values

@return string