pascal case "__toString" is converted to sentence case "Tostring" instead of "To string"

[khalyomede]

The following reproduction code will show the issue:

use Jawira\CaseConverter\Convert;

require __DIR__ . "/vendor/autoload.php";

$original = "__toString";
$text = new Convert($original);
$expected = "To string";
$sentence = $text->toSentence();

echo $expected === $sentence
    ? "$expected === $sentence" . PHP_EOL
    : "Expected $sentence to be $expected";

echo PHP_EOL;

Expected Tostring to be To string

Is it expected?

FYI here is how one NPM package handles it (as expected in my opinion)