private static void checkLog4jProperties() {
    String filename = "log4j.properties";
    try (final InputStream inStream =
      CatalogJanitor.class.getClassLoader().getResourceAsStream(filename)) {
      if (inStream != null) {
        new Properties().load(inStream);
      } else {
        System.out.println("No " + filename + " on classpath; Add one else no logging output!");
      }
    } catch (IOException e) {
      LOG.error("Log4j check failed", e);
    }
  }
Checks if a region still holds references to parent.
@param tableName The table for the region
@param region    The region to check
@return A pair where the first boolean says whether the region directory exists in the
        filesystem and then the second boolean says whether the region has references to a
        parent.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/janitor/CatalogJanitor.java