public static Object[] randomWritablePrimitiveRow(int columnCount, Random r,
      PrimitiveTypeInfo[] primitiveTypeInfos) {
    return randomWritablePrimitiveRow(columnCount, r, primitiveTypeInfos, null);
  }
Generate object inspector and random row object[].
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/VectorRandomRowSource.java