VectorSpillBlock get(int i) {
    return blocks.get(i);
  }
Reads a single row from a VectorRowBytesContainer. Caller is responsible for calling and
checking readNext in advance.

@param batch
@param vectorDeserializeRow
@param rowBytesContainer
@throws HiveException
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/ptf/VectorSpillBlockContainer.java