public function createFeedback(Certificate $certificate = null)
	{
		// Check if a certificate is given, if not use the default certificate
		if (null == $certificate && $this->getCertificateFactory() != null) {
			$certificate = $this->getCertificateFactory()->getDefaultCertificate();
		}

		// Check if there is a certificate to use after falling back on the default certificate
		if (null == $certificate) {
			throw new \RuntimeException('No certificate given for the creation of the feedback service and no default certificate available.');
		}

		return new Feedback($certificate);
	}