@Override
    public ByteBuffer getByteBufferRaw() {
      return bb;
    }
The fake buffer that emulates end of file, with footer length and magic. Given that these
can be generated based on the footer buffer itself, we don't cache them.
ql/src/java/org/apache/hadoop/hive/ql/io/parquet/vector/ParquetFooterInputFromCache.java