constructor(issuedAt: Instant, validUntil: Instant, timeZone: TimeZone?, nonce: ByteArray, attestationEndpoint: String, proofOID: ObjectIdentifier) Convenience constructor to pass two instants instead of instant and duration
constructor(issuedAt: Instant, validity: Duration? = null, timeZone: TimeZone? = null, nonce: ByteArray, attestationEndpoint: String, proofOID: ObjectIdentifier)