presto-rcfile/src/main/java/io/prestosql/rcfile/binary/DateEncoding.java/DateEncoding/decodeValueInto
class DateEncoding:    @Override
    public void decodeValueInto(BlockBuilder builder, Slice slice, int offset, int length)
    {
        long daysSinceEpoch = readVInt(slice, offset, length);
        type.writeLong(builder, daysSinceEpoch);
    }