What does StringObservableTest.testFromReaderWillUnsubscribeBeforeCallingNextRead() test? #42

@Test
public void testFromReaderWillUnsubscribeBeforeCallingNextRead() {
  final byte[] inBytes = "test".getBytes();
  final AtomicInteger numReads = new AtomicInteger(0);
  ByteArrayInputStream is = new ByteArrayInputStream(inBytes) {


    @Override
    public synchronized int read(byte[] b, int off, int len) {
      numReads.incrementAndGet();
      return super.read(b, off, len);
    }
  };
  StringObservable.from(new InputStreamReader(is)).first().toBlocking().single();
  assertEquals(1, numReads.get());
}