@Override
  public @Nullable SplitResult<TimestampRange> trySplit(double fractionOfRemainder) {
    if (InitialPartition.isInitialPartition(partition.getPartitionToken())) {
      return null;
    }

    return super.trySplit(fractionOfRemainder);
  }
@Test
  public void testTrySplitReturnsNullForInitialPartition() {
    when(partition.getPartitionToken()).thenReturn(InitialPartition.PARTITION_TOKEN);

    assertNull(tracker.trySplit(0.0D));
  }