src/Signer/Rsa.php
final public function sign(string $payload, Key $key): string
    {
        return $this->createSignature($key->getContent(), $key->getPassphrase(), $payload);
    }
final public function sign(string $payload, Key $key): string
    {
        return $this->createSignature($key->getContent(), $key->getPassphrase(), $payload);
    }
{@inheritdoc}