private void checkStream(int size, int buffer) throws IOException {
Random rand = new Random();
byte[] data = new byte[size];
rand.nextBytes(data);
Directory dir = new RAMDirectory();
IndexOutput out = dir.createOutput("test");
out.writeBytes(data, data.length);
out.close();
InputStream in = new IndexInputStream(dir.openInput("test"));
if (buffer != 0) {
in = new BufferedInputStream(in, buffer);