private MultiPartIterator(List<Part> parts) {
this.parts = parts;
if (parts.isEmpty()) {
iterator = Stream.of(onlyBoundary.slice()).iterator();
} else {
List<ByteBuffer> list = new ArrayList<>();
for (int i = 0; i < parts.size(); ++i) {
Part part = parts.get(i);
if (i == 0) list.add(firstBoundary.slice());
else list.add(middleBoundary.slice());
list.addAll(part.getByteBuffers());
}
list.add(lastBoundary.slice());
iterator = list.iterator();
}
}
