Steps to reproduce the issue

$toolbar = Toolbar::getInstance(); $toolbar->back('foobar');

Expected result

<a href="javascript:history.back();">foobar</a>

Actual result

<a href="javascript:history.back();">back</a>

System information (as much as possible)

5.2.0

Additional comments

public function back(string $text = 'JTOOLBAR_BACK'): LinkButton
    {
        return $this->link('back', $text)
            ->url('javascript:history.back();');
    }

Solution:

public function back(string $text = 'JTOOLBAR_BACK'): LinkButton
    {
        return $this->link($text, 'javascript:history.back();');
    }