NonceAccount constructor

const NonceAccount({
  1. required int version,
  2. required int state,
  3. required Pubkey authorizedPubkey,
  4. required String nonce,
  5. required FeeCalculator feeCalculator,
})

https://docs.solana.com/offline-signing/durable-nonce

Durable transaction nonces are a mechanism for getting around the typical short lifetime of a transaction's recent_blockhash.

Each transaction submitted on Solana must specify a recent blockhash that was generated within 2 minutes of the latest blockhash. If it takes longer than 2 minutes to get everybody’s signatures, then you have to use nonce accounts.

For example, nonce accounts are used in cases when you need multiple people to sign a transaction, but they can’t all be available to sign it on the same computer within a short enough time period.

Implementation

const NonceAccount({
  required this.version,
  required this.state,
  required this.authorizedPubkey,
  required this.nonce,
  required this.feeCalculator,
});