let nextnextKey = await agent.keyManagerCreate({
    kms: 'local',
    type: 'Ed25519',
});
// nextKey is outside of this scope
let nextKeySai = prefixedDerivative(
    b64EncodeUrlSafe(
        Uint8Array.from(Buffer.from(nextKey.publicKeyHex, 'hex'))
    )
);
let nextnextKeySai = prefixedDerivative(
    b64EncodeUrlSafe(
        Uint8Array.from(Buffer.from(nextnextKey.publicKeyHex, 'hex'))
    )
);
// prefix is outside of this scope
let controller = new keri.Controller(
    prefix
);

let rotationEvent = controller.rotate([[nextKeySai, nextnextKeySai]]);

const signature = await agent.keyManagerSign({
    keyRef: nextKey.publicKeyHex,
    data: rotationEvent,
});

let result = controller.finalizeRotation(rotationEvent, [
    prefixedSignature(
        b64EncodeUrlSafe(
            Uint8Array.from(Buffer.from(signature, 'base64'))
        )
    ),
]);