SchnorrkelSecretKey.fromEd25519 constructor
Creates a SchnorrkelSecretKey instance from a byte representation of an Ed25519 secret key.
Parameters:
secretKeyBytes: A byte array representing an Ed25519 secret key.
Returns:
A SchnorrkelSecretKey instance derived from the provided Ed25519 secret key representation.
Throws:
- An 
ArgumentExceptionif the byte array does not have the correct length for a secret key. 
Implementation
factory SchnorrkelSecretKey.fromEd25519(List<int> secretKeyBytes) {
  _KeyUtils._checkKeysBytes(
      secretKeyBytes, SchnorrkelKeyCost.secretKeyLength, "secret key");
  final newKey = List<int>.from(
      secretKeyBytes.sublist(0, SchnorrkelKeyCost.miniSecretLength));
  _KeyUtils.divideScalarByCofactor(newKey);
  return SchnorrkelSecretKey(
      BytesUtils.toBytes(newKey, unmodifiable: true),
      BytesUtils.toBytes(
          secretKeyBytes.sublist(SchnorrkelKeyCost.miniSecretLength,
              SchnorrkelKeyCost.secretKeyLength),
          unmodifiable: true));
}