Screaming Snake Case Keys to Camel Case

[bebetoalves]

I don't know if it was a team decision and I didn't find anything about it either, but apparently the camelCaseKeys method doesn't work with screaming snake case keys.

class User
{
    public string $firstName;
}

$source = Source::array([['FIRST_NAME' => 'John'], ['FIRST_NAME' => 'Jane']])
    ->camelCaseKeys();

$users = (new MapperBuilder())
    ->allowSuperfluousKeys()
    ->mapper()
    ->map('User[]', $source); // throws exception