mr-legend_wiki/inc/Parsing/ParserMode/Header.php

<?php

namespace dokuwiki\Parsing\ParserMode;

class Header extends AbstractMode
{
    /** @inheritdoc */
    public function connectTo($mode)
    {
        //we're not picky about the closing ones, two are enough
        $this->Lexer->addSpecialPattern(
            '[ \t]*={2,}[^\n]+={2,}[ \t]*(?=\n)',
            $mode,
            'header'
        );
    }

    /** @inheritdoc */
    public function getSort()
    {
        return 50;
    }
}