@Override
  protected void setup(Context context) {
    doSetup(context);
  }
Dummy mapper used for unit tests to verify that the mapper can be injected. This approach would
be used if a custom transformation needed to be done after reading the input data before writing
it to HFiles.
hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/mapreduce/TsvImporterCustomTestMapper.java