public function getContentKeyAuthorizationPolicy($contentKeyAuthorizationPolicy)
    {
        $contentKeyAuthorizationPolicyId = Utilities::getEntityId(
            $contentKeyAuthorizationPolicy,
            'WindowsAzure\MediaServices\Models\ContentKeyAuthorizationPolicy'
        );

        return ContentKeyAuthorizationPolicy::createFromOptions(
            $this->_getEntity("ContentKeyAuthorizationPolicies('{$contentKeyAuthorizationPolicyId}')")
        );
    }