@GetInitialRestriction
  public OffsetByteRange getInitialRestriction(
      @Element SubscriptionPartition subscriptionPartition) {
    Offset offset = offsetReaderFactory.apply(subscriptionPartition).read();
    return OffsetByteRange.of(new OffsetRange(offset.value(), Long.MAX_VALUE /* open interval */));
  }
@Test
  public void getInitialRestrictionReadSuccess() {
    when(initialOffsetReader.read()).thenReturn(example(Offset.class));
    OffsetByteRange range = sdf.getInitialRestriction(PARTITION);
    assertEquals(example(Offset.class).value(), range.getRange().getFrom());
    assertEquals(Long.MAX_VALUE, range.getRange().getTo());
    assertEquals(0, range.getByteCount());
    verify(offsetReaderFactory).apply(PARTITION);
  }