@Test
  public void testSecondaryRegionWithNonEmptyRegion() throws IOException {
    // Create a new table with region replication and load some data
    // than disable and enable the table again and verify the data from secondary
    try (Connection connection = ConnectionFactory.createConnection(HTU.getConfiguration());
      Table table = connection.getTable(htd.getTableName())) {

      HTU.loadNumericRows(table, fam, 0, 1000);

      HTU.getAdmin().disableTable(htd.getTableName());
      HTU.getAdmin().enableTable(htd.getTableName());

      HTU.verifyNumericRows(table, fam, 0, 1000, 1);
    }
  }
Tests the case where if there is some data in the primary region, reopening the region replicas
(enable/disable table, etc) makes the region replicas readable.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestRegionReplicaFailover.java