protected function maybeCompressCombineHeadJs($html)
    {
        if (($benchmark = !empty($this->options['benchmark']) && $this->options['benchmark'] === 'details')) {
            $time = microtime(true);
        }
        $html = (string) $html; // Force string value.

        if (isset($this->options['compress_combine_head_js'])) {
            if (!$this->options['compress_combine_head_js']) {
                $disabled = true; // Disabled flag.
            }
        }
        if (!$html || !empty($disabled)) {
            goto finale; // Nothing to do.
        }
        if (($head_frag = $this->getHeadFrag($html)) /* No need to get the HTML frag here; we're operating on the `<head>` only. */) {
            if (($js_tag_frags = $this->getJsTagFrags($head_frag)) && ($js_parts = $this->compileJsTagFragsIntoParts($js_tag_frags, 'head'))) {
                $js_tag_frags_all_compiled = $this->compileKeyElementsDeep($js_tag_frags, 'all');
                $html                      = $this->replaceOnce($head_frag['all'], '%%htmlc-head%%', $html);
                $cleaned_head_contents     = $this->replaceOnce($js_tag_frags_all_compiled, '', $head_frag['contents']);
                $cleaned_head_contents     = $this->cleanupSelfClosingHtmlTagLines($cleaned_head_contents);

                $compressed_js_tags = []; // Initialize.

                foreach ($js_parts as $_js_part) {
                    if (isset($_js_part['exclude_frag'], $js_tag_frags[$_js_part['exclude_frag']]['all'])) {
                        $compressed_js_tags[] = $js_tag_frags[$_js_part['exclude_frag']]['all'];
                    } else {
                        $compressed_js_tags[] = $_js_part['tag'];
                    }
                } // unset($_js_part); // Housekeeping.

                $compressed_js_tags    = implode("\n", $compressed_js_tags);
                $compressed_head_parts = [$head_frag['open_tag'], $cleaned_head_contents, $compressed_js_tags, $head_frag['closing_tag']];
                $html                  = $this->replaceOnce('%%htmlc-head%%', implode("\n", $compressed_head_parts), $html);

                if ($benchmark) {
                    $this->benchmark->addData(
                        __FUNCTION__,
                        compact(
                            'head_frag',
                            'js_tag_frags',
                            'js_parts',
                            'cleaned_head_contents',
                            'compressed_js_tags',
                            'compressed_head_parts'
                        )
                    );
                }
            }
        }
        finale: // Target point; finale/return value.

        if ($html) {
            $html = trim($html);
        } // Trim it up now!

        if ($benchmark && !empty($time) && $html && empty($disabled)) {
            $this->benchmark->addTime(
                __FUNCTION__,
                $time, // Caller, start time, task performed.
                sprintf('compressing/combining head JS in checksum: `%1$s`', md5($html))
            );
        }
        return $html; // With possible compression having been applied here.
    }