@Override
  public void add(int sourceColumn, int outputColumn, TypeInfo typeInfo) {
    // Order on sourceColumn.
    vectorColumnMapping.add(sourceColumn, outputColumn, typeInfo);
  }
This class collects column information for copying a row from one VectorizedRowBatch to
same/another batch.

In this variation, column information is ordered by the source column number.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorColumnSourceMapping.java