@Test
  public void test() throws Exception {
    // create a table so that we will write some edits to meta
    TableName tableName = TableName.valueOf("whatever");
    UTIL.createTable(tableName, Bytes.toBytes("family"));
    UTIL.waitTableAvailable(tableName);
    HRegionServer rs = UTIL.getMiniHBaseCluster().getRegionServer(0);
    Path walDir = new Path(rs.getWALRootDir(),
      AbstractFSWALProvider.getWALDirectoryName(rs.getServerName().toString()));
    // we should have meta wal files.
    assertTrue(
      rs.getWALFileSystem().listStatus(walDir, AbstractFSWALProvider::isMetaFile).length > 0);
  }
Testcase for HBASE-21843. Used to confirm that we use the correct name for meta wal file when
using {@link RegionGroupingProvider}.
hbase-server/src/test/java/org/apache/hadoop/hbase/wal/TestWrongMetaWALFileName.java