code: @Override
      public void read(final Reader reader) throws ConfigurationException, IOException {
          Preconditions.checkNotNull(reader);
  
          final HashMap<String, Object> settings = this.mapper.readValue(reader, HASH_MAP_TYPE_REFERENCE);
          final ImmutableNode rootNode = toNode(new Builder(), settings);
          this.getSubConfigurationParentModel().mergeRoot(rootNode, null, null, null, this);
      }
docs: Reads the configuration.
  
  @param reader The reader to read from.
  @throws ConfigurationException
  @throws IOException