@Override public ReaderKey getKey() {
      return key;
    }
Create a reader that reads from the first key larger than minKey to any
keys equal to maxKey.
@param key the key to read into
@param reader the ORC file reader
@param minKey only return keys larger than minKey if it is non-null
@param maxKey only return keys less than or equal to maxKey if it is
              non-null
@param options options to provide to read the rows.
@param conf
@throws IOException
ql/src/java/org/apache/hadoop/hive/ql/io/orc/OrcRawRecordMerger.java