private HRegion getRegion(final Configuration conf, final String tableName) throws IOException {
    FSHLog wal = new FSHLog(FileSystem.get(conf), TEST_UTIL.getDataTestDir(),
      TEST_UTIL.getDataTestDir().toString(), conf);
    wal.init();
    ChunkCreator.initialize(MemStoreLAB.CHUNK_SIZE_DEFAULT, false, 0, 0, 0, null,
      MemStoreLAB.INDEX_CHUNK_SIZE_PERCENTAGE_DEFAULT);
    return TEST_UTIL.createLocalHRegion(TableName.valueOf(tableName), HConstants.EMPTY_BYTE_ARRAY,
      HConstants.EMPTY_BYTE_ARRAY, conf, false, Durability.SKIP_WAL, wal, INCREMENT_BYTES);
  }
Increments with some concurrency against a region to ensure we get the right answer. Test is
parameterized to run the fast and slow path increments; if fast,
HRegion.INCREMENT_FAST_BUT_NARROW_CONSISTENCY_KEY is true.
<p>
There is similar test up in TestAtomicOperation. It does a test where it has 100 threads doing
increments across two column families all on one row and the increments are connected to prove
atomicity on row.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestRegionIncrement.java