@Override
    public int peekNextBufferSubpartitionId() throws IOException {
        if (subpartitionId >= 0) {
            return subpartitionId;
        }
        return subpartitionView.peekNextBufferSubpartitionId();
    }
@Test
    void testPeekNextBufferSubpartitionId() throws Exception {
        int numCredits = 2;
        CreditBasedSequenceNumberingViewReader reader = createNetworkSequenceViewReader(numCredits);
        assertThat(reader.peekNextBufferSubpartitionId()).isZero();
    }