multiply method

Implementation

@override
JubJubNativePoint multiply(List<int> by) {
  assert(by.length == 32);
  final zero = JubJubAffineNielsNativePoint.identity();
  JubJubNativePoint acc = JubJubNativePoint.identity();
  final bits = BytesUtils.bytesToBits(by);
  final iterableBits = bits.reversed.skip(4);
  for (final bit in iterableBits) {
    acc = acc.double();
    acc += bit ? this : zero;
  }
  return acc;
}