getAmountBytes method
Converts the current amount (BigInt) to an 8-byte little-endian array.
Implementation
ByteArray getAmountBytes() {
final buffer = Uint8List(TXAMOUNT);
final byteData = ByteData.view(buffer.buffer);
// Convert BigInt to int for putUint64. This assumes the BigInt fits in 64 bits.
byteData.setUint64(0, _amount.toInt(), Endian.little);
return buffer;
}