} else {
return d1.from().compareTo(d2.from());
}
}
}
<BUG>private static class BlockComparator implements Comparator<Block> {
</BUG>
private static final long serialVersionUID = 1;
@Override
public int compare(@Nullable Block b1,

} else {
return d1.from().compareTo(d2.from());
}
}
}
private static class BlockComparator implements Comparator<Block>, Serializable {
private static final long serialVersionUID = 1;
@Override
public int compare(@Nullable Block b1,
