$result = SafeMarkup::format($string, $args);
$this->assertEquals($expected, (string) $result, $message);
$this->assertEquals($expected_is_safe, $result instanceof MarkupInterface, 'SafeMarkup::format correctly sets the result as safe or not safe.');
$result = SafeMarkup::format($string, $args);
$this->assertEquals($expected, (string) $result, $message);
$this->assertEquals($expected_is_safe, $result instanceof MarkupInterface, 'SafeMarkup::format correctly sets the result as safe or not safe.');