code: public static Map<String, String> getUnsupportedFeatures(HColumnDescriptor columnDescriptor) {
      Map<String, String> unsupportedConfiguration = new HashMap<String, String>();
  
      Map<String, String> configuration = columnDescriptor.getConfiguration();
      for (Map.Entry<String, String> entry : SUPPORTED_OPTION_VALUES.entrySet()) {
        if (configuration.containsKey(entry.getKey())
            && configuration.get(entry.getKey()) != null
            && !entry.getValue().equals(configuration.get(entry.getKey()))) {
          unsupportedConfiguration.put(entry.getKey(), configuration.get(entry.getKey()));
        }
      }
      return unsupportedConfiguration;
    }
docs: Build a Map of configuration keys and values describing configuration values we don't support.
  
  @param columnDescriptor a {@link org.apache.hadoop.hbase.HColumnDescriptor} object.
  @return a {@link java.util.Map} object.